1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_gzio.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/imgact.h> 56 #include <sys/kernel.h> 57 #include <sys/ktr.h> 58 #include <sys/ktrace.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mutex.h> 62 #include <sys/refcount.h> 63 #include <sys/namei.h> 64 #include <sys/proc.h> 65 #include <sys/procdesc.h> 66 #include <sys/posix4.h> 67 #include <sys/pioctl.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sdt.h> 71 #include <sys/sbuf.h> 72 #include <sys/sleepqueue.h> 73 #include <sys/smp.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysent.h> 79 #include <sys/syslog.h> 80 #include <sys/sysproto.h> 81 #include <sys/timers.h> 82 #include <sys/unistd.h> 83 #include <sys/wait.h> 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/uma.h> 87 88 #include <sys/jail.h> 89 90 #include <machine/cpu.h> 91 92 #include <security/audit/audit.h> 93 94 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 95 96 SDT_PROVIDER_DECLARE(proc); 97 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *", 98 "struct proc *", "int"); 99 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int", 100 "ksiginfo_t *"); 101 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard, 102 "struct thread *", "struct proc *", "int"); 103 104 static int coredump(struct thread *); 105 static int killpg1(struct thread *td, int sig, int pgid, int all, 106 ksiginfo_t *ksi); 107 static int issignal(struct thread *td); 108 static int sigprop(int sig); 109 static void tdsigwakeup(struct thread *, int, sig_t, int); 110 static void sig_suspend_threads(struct thread *, struct proc *, int); 111 static int filt_sigattach(struct knote *kn); 112 static void filt_sigdetach(struct knote *kn); 113 static int filt_signal(struct knote *kn, long hint); 114 static struct thread *sigtd(struct proc *p, int sig, int prop); 115 static void sigqueue_start(void); 116 117 static uma_zone_t ksiginfo_zone = NULL; 118 struct filterops sig_filtops = { 119 .f_isfd = 0, 120 .f_attach = filt_sigattach, 121 .f_detach = filt_sigdetach, 122 .f_event = filt_signal, 123 }; 124 125 static int kern_logsigexit = 1; 126 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 127 &kern_logsigexit, 0, 128 "Log processes quitting on abnormal signals to syslog(3)"); 129 130 static int kern_forcesigexit = 1; 131 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 132 &kern_forcesigexit, 0, "Force trap signal to be handled"); 133 134 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 135 "POSIX real time signal"); 136 137 static int max_pending_per_proc = 128; 138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 139 &max_pending_per_proc, 0, "Max pending signals per proc"); 140 141 static int preallocate_siginfo = 1024; 142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 143 &preallocate_siginfo, 0, "Preallocated signal memory size"); 144 145 static int signal_overflow = 0; 146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 147 &signal_overflow, 0, "Number of signals overflew"); 148 149 static int signal_alloc_fail = 0; 150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 151 &signal_alloc_fail, 0, "signals failed to be allocated"); 152 153 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 154 155 /* 156 * Policy -- Can ucred cr1 send SIGIO to process cr2? 157 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 158 * in the right situations. 159 */ 160 #define CANSIGIO(cr1, cr2) \ 161 ((cr1)->cr_uid == 0 || \ 162 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 163 (cr1)->cr_uid == (cr2)->cr_ruid || \ 164 (cr1)->cr_ruid == (cr2)->cr_uid || \ 165 (cr1)->cr_uid == (cr2)->cr_uid) 166 167 static int sugid_coredump; 168 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 169 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 170 171 static int capmode_coredump; 172 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 173 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 174 175 static int do_coredump = 1; 176 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 177 &do_coredump, 0, "Enable/Disable coredumps"); 178 179 static int set_core_nodump_flag = 0; 180 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 181 0, "Enable setting the NODUMP flag on coredump files"); 182 183 static int coredump_devctl = 0; 184 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 185 0, "Generate a devctl notification when processes coredump"); 186 187 /* 188 * Signal properties and actions. 189 * The array below categorizes the signals and their default actions 190 * according to the following properties: 191 */ 192 #define SA_KILL 0x01 /* terminates process by default */ 193 #define SA_CORE 0x02 /* ditto and coredumps */ 194 #define SA_STOP 0x04 /* suspend process */ 195 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 196 #define SA_IGNORE 0x10 /* ignore by default */ 197 #define SA_CONT 0x20 /* continue if suspended */ 198 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 199 200 static int sigproptbl[NSIG] = { 201 SA_KILL, /* SIGHUP */ 202 SA_KILL, /* SIGINT */ 203 SA_KILL|SA_CORE, /* SIGQUIT */ 204 SA_KILL|SA_CORE, /* SIGILL */ 205 SA_KILL|SA_CORE, /* SIGTRAP */ 206 SA_KILL|SA_CORE, /* SIGABRT */ 207 SA_KILL|SA_CORE, /* SIGEMT */ 208 SA_KILL|SA_CORE, /* SIGFPE */ 209 SA_KILL, /* SIGKILL */ 210 SA_KILL|SA_CORE, /* SIGBUS */ 211 SA_KILL|SA_CORE, /* SIGSEGV */ 212 SA_KILL|SA_CORE, /* SIGSYS */ 213 SA_KILL, /* SIGPIPE */ 214 SA_KILL, /* SIGALRM */ 215 SA_KILL, /* SIGTERM */ 216 SA_IGNORE, /* SIGURG */ 217 SA_STOP, /* SIGSTOP */ 218 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 219 SA_IGNORE|SA_CONT, /* SIGCONT */ 220 SA_IGNORE, /* SIGCHLD */ 221 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 222 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 223 SA_IGNORE, /* SIGIO */ 224 SA_KILL, /* SIGXCPU */ 225 SA_KILL, /* SIGXFSZ */ 226 SA_KILL, /* SIGVTALRM */ 227 SA_KILL, /* SIGPROF */ 228 SA_IGNORE, /* SIGWINCH */ 229 SA_IGNORE, /* SIGINFO */ 230 SA_KILL, /* SIGUSR1 */ 231 SA_KILL, /* SIGUSR2 */ 232 }; 233 234 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 235 236 static void 237 sigqueue_start(void) 238 { 239 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 240 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 241 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 242 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 243 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 244 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 245 } 246 247 ksiginfo_t * 248 ksiginfo_alloc(int wait) 249 { 250 int flags; 251 252 flags = M_ZERO; 253 if (! wait) 254 flags |= M_NOWAIT; 255 if (ksiginfo_zone != NULL) 256 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 257 return (NULL); 258 } 259 260 void 261 ksiginfo_free(ksiginfo_t *ksi) 262 { 263 uma_zfree(ksiginfo_zone, ksi); 264 } 265 266 static __inline int 267 ksiginfo_tryfree(ksiginfo_t *ksi) 268 { 269 if (!(ksi->ksi_flags & KSI_EXT)) { 270 uma_zfree(ksiginfo_zone, ksi); 271 return (1); 272 } 273 return (0); 274 } 275 276 void 277 sigqueue_init(sigqueue_t *list, struct proc *p) 278 { 279 SIGEMPTYSET(list->sq_signals); 280 SIGEMPTYSET(list->sq_kill); 281 TAILQ_INIT(&list->sq_list); 282 list->sq_proc = p; 283 list->sq_flags = SQ_INIT; 284 } 285 286 /* 287 * Get a signal's ksiginfo. 288 * Return: 289 * 0 - signal not found 290 * others - signal number 291 */ 292 static int 293 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 294 { 295 struct proc *p = sq->sq_proc; 296 struct ksiginfo *ksi, *next; 297 int count = 0; 298 299 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 300 301 if (!SIGISMEMBER(sq->sq_signals, signo)) 302 return (0); 303 304 if (SIGISMEMBER(sq->sq_kill, signo)) { 305 count++; 306 SIGDELSET(sq->sq_kill, signo); 307 } 308 309 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 310 if (ksi->ksi_signo == signo) { 311 if (count == 0) { 312 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 313 ksi->ksi_sigq = NULL; 314 ksiginfo_copy(ksi, si); 315 if (ksiginfo_tryfree(ksi) && p != NULL) 316 p->p_pendingcnt--; 317 } 318 if (++count > 1) 319 break; 320 } 321 } 322 323 if (count <= 1) 324 SIGDELSET(sq->sq_signals, signo); 325 si->ksi_signo = signo; 326 return (signo); 327 } 328 329 void 330 sigqueue_take(ksiginfo_t *ksi) 331 { 332 struct ksiginfo *kp; 333 struct proc *p; 334 sigqueue_t *sq; 335 336 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 337 return; 338 339 p = sq->sq_proc; 340 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 341 ksi->ksi_sigq = NULL; 342 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 343 p->p_pendingcnt--; 344 345 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 346 kp = TAILQ_NEXT(kp, ksi_link)) { 347 if (kp->ksi_signo == ksi->ksi_signo) 348 break; 349 } 350 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 351 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 352 } 353 354 static int 355 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 356 { 357 struct proc *p = sq->sq_proc; 358 struct ksiginfo *ksi; 359 int ret = 0; 360 361 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 362 363 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 364 SIGADDSET(sq->sq_kill, signo); 365 goto out_set_bit; 366 } 367 368 /* directly insert the ksi, don't copy it */ 369 if (si->ksi_flags & KSI_INS) { 370 if (si->ksi_flags & KSI_HEAD) 371 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 372 else 373 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 374 si->ksi_sigq = sq; 375 goto out_set_bit; 376 } 377 378 if (__predict_false(ksiginfo_zone == NULL)) { 379 SIGADDSET(sq->sq_kill, signo); 380 goto out_set_bit; 381 } 382 383 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 384 signal_overflow++; 385 ret = EAGAIN; 386 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 387 signal_alloc_fail++; 388 ret = EAGAIN; 389 } else { 390 if (p != NULL) 391 p->p_pendingcnt++; 392 ksiginfo_copy(si, ksi); 393 ksi->ksi_signo = signo; 394 if (si->ksi_flags & KSI_HEAD) 395 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 396 else 397 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 398 ksi->ksi_sigq = sq; 399 } 400 401 if ((si->ksi_flags & KSI_TRAP) != 0 || 402 (si->ksi_flags & KSI_SIGQ) == 0) { 403 if (ret != 0) 404 SIGADDSET(sq->sq_kill, signo); 405 ret = 0; 406 goto out_set_bit; 407 } 408 409 if (ret != 0) 410 return (ret); 411 412 out_set_bit: 413 SIGADDSET(sq->sq_signals, signo); 414 return (ret); 415 } 416 417 void 418 sigqueue_flush(sigqueue_t *sq) 419 { 420 struct proc *p = sq->sq_proc; 421 ksiginfo_t *ksi; 422 423 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 424 425 if (p != NULL) 426 PROC_LOCK_ASSERT(p, MA_OWNED); 427 428 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 429 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 430 ksi->ksi_sigq = NULL; 431 if (ksiginfo_tryfree(ksi) && p != NULL) 432 p->p_pendingcnt--; 433 } 434 435 SIGEMPTYSET(sq->sq_signals); 436 SIGEMPTYSET(sq->sq_kill); 437 } 438 439 static void 440 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 441 { 442 sigset_t tmp; 443 struct proc *p1, *p2; 444 ksiginfo_t *ksi, *next; 445 446 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 447 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 448 p1 = src->sq_proc; 449 p2 = dst->sq_proc; 450 /* Move siginfo to target list */ 451 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 452 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 453 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 454 if (p1 != NULL) 455 p1->p_pendingcnt--; 456 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 457 ksi->ksi_sigq = dst; 458 if (p2 != NULL) 459 p2->p_pendingcnt++; 460 } 461 } 462 463 /* Move pending bits to target list */ 464 tmp = src->sq_kill; 465 SIGSETAND(tmp, *set); 466 SIGSETOR(dst->sq_kill, tmp); 467 SIGSETNAND(src->sq_kill, tmp); 468 469 tmp = src->sq_signals; 470 SIGSETAND(tmp, *set); 471 SIGSETOR(dst->sq_signals, tmp); 472 SIGSETNAND(src->sq_signals, tmp); 473 } 474 475 #if 0 476 static void 477 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 478 { 479 sigset_t set; 480 481 SIGEMPTYSET(set); 482 SIGADDSET(set, signo); 483 sigqueue_move_set(src, dst, &set); 484 } 485 #endif 486 487 static void 488 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 489 { 490 struct proc *p = sq->sq_proc; 491 ksiginfo_t *ksi, *next; 492 493 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 494 495 /* Remove siginfo queue */ 496 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 497 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 498 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 499 ksi->ksi_sigq = NULL; 500 if (ksiginfo_tryfree(ksi) && p != NULL) 501 p->p_pendingcnt--; 502 } 503 } 504 SIGSETNAND(sq->sq_kill, *set); 505 SIGSETNAND(sq->sq_signals, *set); 506 } 507 508 void 509 sigqueue_delete(sigqueue_t *sq, int signo) 510 { 511 sigset_t set; 512 513 SIGEMPTYSET(set); 514 SIGADDSET(set, signo); 515 sigqueue_delete_set(sq, &set); 516 } 517 518 /* Remove a set of signals for a process */ 519 static void 520 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 521 { 522 sigqueue_t worklist; 523 struct thread *td0; 524 525 PROC_LOCK_ASSERT(p, MA_OWNED); 526 527 sigqueue_init(&worklist, NULL); 528 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 529 530 FOREACH_THREAD_IN_PROC(p, td0) 531 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 532 533 sigqueue_flush(&worklist); 534 } 535 536 void 537 sigqueue_delete_proc(struct proc *p, int signo) 538 { 539 sigset_t set; 540 541 SIGEMPTYSET(set); 542 SIGADDSET(set, signo); 543 sigqueue_delete_set_proc(p, &set); 544 } 545 546 static void 547 sigqueue_delete_stopmask_proc(struct proc *p) 548 { 549 sigset_t set; 550 551 SIGEMPTYSET(set); 552 SIGADDSET(set, SIGSTOP); 553 SIGADDSET(set, SIGTSTP); 554 SIGADDSET(set, SIGTTIN); 555 SIGADDSET(set, SIGTTOU); 556 sigqueue_delete_set_proc(p, &set); 557 } 558 559 /* 560 * Determine signal that should be delivered to thread td, the current 561 * thread, 0 if none. If there is a pending stop signal with default 562 * action, the process stops in issignal(). 563 */ 564 int 565 cursig(struct thread *td) 566 { 567 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 568 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 569 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 570 return (SIGPENDING(td) ? issignal(td) : 0); 571 } 572 573 /* 574 * Arrange for ast() to handle unmasked pending signals on return to user 575 * mode. This must be called whenever a signal is added to td_sigqueue or 576 * unmasked in td_sigmask. 577 */ 578 void 579 signotify(struct thread *td) 580 { 581 struct proc *p; 582 583 p = td->td_proc; 584 585 PROC_LOCK_ASSERT(p, MA_OWNED); 586 587 if (SIGPENDING(td)) { 588 thread_lock(td); 589 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 590 thread_unlock(td); 591 } 592 } 593 594 int 595 sigonstack(size_t sp) 596 { 597 struct thread *td = curthread; 598 599 return ((td->td_pflags & TDP_ALTSTACK) ? 600 #if defined(COMPAT_43) 601 ((td->td_sigstk.ss_size == 0) ? 602 (td->td_sigstk.ss_flags & SS_ONSTACK) : 603 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 604 #else 605 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 606 #endif 607 : 0); 608 } 609 610 static __inline int 611 sigprop(int sig) 612 { 613 614 if (sig > 0 && sig < NSIG) 615 return (sigproptbl[_SIG_IDX(sig)]); 616 return (0); 617 } 618 619 int 620 sig_ffs(sigset_t *set) 621 { 622 int i; 623 624 for (i = 0; i < _SIG_WORDS; i++) 625 if (set->__bits[i]) 626 return (ffs(set->__bits[i]) + (i * 32)); 627 return (0); 628 } 629 630 static bool 631 sigact_flag_test(const struct sigaction *act, int flag) 632 { 633 634 /* 635 * SA_SIGINFO is reset when signal disposition is set to 636 * ignore or default. Other flags are kept according to user 637 * settings. 638 */ 639 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 640 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 641 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 642 } 643 644 /* 645 * kern_sigaction 646 * sigaction 647 * freebsd4_sigaction 648 * osigaction 649 */ 650 int 651 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 652 struct sigaction *oact, int flags) 653 { 654 struct sigacts *ps; 655 struct proc *p = td->td_proc; 656 657 if (!_SIG_VALID(sig)) 658 return (EINVAL); 659 if (act != NULL && act->sa_handler != SIG_DFL && 660 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 661 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 662 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 663 return (EINVAL); 664 665 PROC_LOCK(p); 666 ps = p->p_sigacts; 667 mtx_lock(&ps->ps_mtx); 668 if (oact) { 669 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 670 oact->sa_flags = 0; 671 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 672 oact->sa_flags |= SA_ONSTACK; 673 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 674 oact->sa_flags |= SA_RESTART; 675 if (SIGISMEMBER(ps->ps_sigreset, sig)) 676 oact->sa_flags |= SA_RESETHAND; 677 if (SIGISMEMBER(ps->ps_signodefer, sig)) 678 oact->sa_flags |= SA_NODEFER; 679 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 680 oact->sa_flags |= SA_SIGINFO; 681 oact->sa_sigaction = 682 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 683 } else 684 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 685 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 686 oact->sa_flags |= SA_NOCLDSTOP; 687 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 688 oact->sa_flags |= SA_NOCLDWAIT; 689 } 690 if (act) { 691 if ((sig == SIGKILL || sig == SIGSTOP) && 692 act->sa_handler != SIG_DFL) { 693 mtx_unlock(&ps->ps_mtx); 694 PROC_UNLOCK(p); 695 return (EINVAL); 696 } 697 698 /* 699 * Change setting atomically. 700 */ 701 702 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 703 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 704 if (sigact_flag_test(act, SA_SIGINFO)) { 705 ps->ps_sigact[_SIG_IDX(sig)] = 706 (__sighandler_t *)act->sa_sigaction; 707 SIGADDSET(ps->ps_siginfo, sig); 708 } else { 709 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 710 SIGDELSET(ps->ps_siginfo, sig); 711 } 712 if (!sigact_flag_test(act, SA_RESTART)) 713 SIGADDSET(ps->ps_sigintr, sig); 714 else 715 SIGDELSET(ps->ps_sigintr, sig); 716 if (sigact_flag_test(act, SA_ONSTACK)) 717 SIGADDSET(ps->ps_sigonstack, sig); 718 else 719 SIGDELSET(ps->ps_sigonstack, sig); 720 if (sigact_flag_test(act, SA_RESETHAND)) 721 SIGADDSET(ps->ps_sigreset, sig); 722 else 723 SIGDELSET(ps->ps_sigreset, sig); 724 if (sigact_flag_test(act, SA_NODEFER)) 725 SIGADDSET(ps->ps_signodefer, sig); 726 else 727 SIGDELSET(ps->ps_signodefer, sig); 728 if (sig == SIGCHLD) { 729 if (act->sa_flags & SA_NOCLDSTOP) 730 ps->ps_flag |= PS_NOCLDSTOP; 731 else 732 ps->ps_flag &= ~PS_NOCLDSTOP; 733 if (act->sa_flags & SA_NOCLDWAIT) { 734 /* 735 * Paranoia: since SA_NOCLDWAIT is implemented 736 * by reparenting the dying child to PID 1 (and 737 * trust it to reap the zombie), PID 1 itself 738 * is forbidden to set SA_NOCLDWAIT. 739 */ 740 if (p->p_pid == 1) 741 ps->ps_flag &= ~PS_NOCLDWAIT; 742 else 743 ps->ps_flag |= PS_NOCLDWAIT; 744 } else 745 ps->ps_flag &= ~PS_NOCLDWAIT; 746 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 747 ps->ps_flag |= PS_CLDSIGIGN; 748 else 749 ps->ps_flag &= ~PS_CLDSIGIGN; 750 } 751 /* 752 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 753 * and for signals set to SIG_DFL where the default is to 754 * ignore. However, don't put SIGCONT in ps_sigignore, as we 755 * have to restart the process. 756 */ 757 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 758 (sigprop(sig) & SA_IGNORE && 759 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 760 /* never to be seen again */ 761 sigqueue_delete_proc(p, sig); 762 if (sig != SIGCONT) 763 /* easier in psignal */ 764 SIGADDSET(ps->ps_sigignore, sig); 765 SIGDELSET(ps->ps_sigcatch, sig); 766 } else { 767 SIGDELSET(ps->ps_sigignore, sig); 768 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 769 SIGDELSET(ps->ps_sigcatch, sig); 770 else 771 SIGADDSET(ps->ps_sigcatch, sig); 772 } 773 #ifdef COMPAT_FREEBSD4 774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 776 (flags & KSA_FREEBSD4) == 0) 777 SIGDELSET(ps->ps_freebsd4, sig); 778 else 779 SIGADDSET(ps->ps_freebsd4, sig); 780 #endif 781 #ifdef COMPAT_43 782 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 784 (flags & KSA_OSIGSET) == 0) 785 SIGDELSET(ps->ps_osigset, sig); 786 else 787 SIGADDSET(ps->ps_osigset, sig); 788 #endif 789 } 790 mtx_unlock(&ps->ps_mtx); 791 PROC_UNLOCK(p); 792 return (0); 793 } 794 795 #ifndef _SYS_SYSPROTO_H_ 796 struct sigaction_args { 797 int sig; 798 struct sigaction *act; 799 struct sigaction *oact; 800 }; 801 #endif 802 int 803 sys_sigaction(td, uap) 804 struct thread *td; 805 register struct sigaction_args *uap; 806 { 807 struct sigaction act, oact; 808 register struct sigaction *actp, *oactp; 809 int error; 810 811 actp = (uap->act != NULL) ? &act : NULL; 812 oactp = (uap->oact != NULL) ? &oact : NULL; 813 if (actp) { 814 error = copyin(uap->act, actp, sizeof(act)); 815 if (error) 816 return (error); 817 } 818 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 819 if (oactp && !error) 820 error = copyout(oactp, uap->oact, sizeof(oact)); 821 return (error); 822 } 823 824 #ifdef COMPAT_FREEBSD4 825 #ifndef _SYS_SYSPROTO_H_ 826 struct freebsd4_sigaction_args { 827 int sig; 828 struct sigaction *act; 829 struct sigaction *oact; 830 }; 831 #endif 832 int 833 freebsd4_sigaction(td, uap) 834 struct thread *td; 835 register struct freebsd4_sigaction_args *uap; 836 { 837 struct sigaction act, oact; 838 register struct sigaction *actp, *oactp; 839 int error; 840 841 842 actp = (uap->act != NULL) ? &act : NULL; 843 oactp = (uap->oact != NULL) ? &oact : NULL; 844 if (actp) { 845 error = copyin(uap->act, actp, sizeof(act)); 846 if (error) 847 return (error); 848 } 849 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 850 if (oactp && !error) 851 error = copyout(oactp, uap->oact, sizeof(oact)); 852 return (error); 853 } 854 #endif /* COMAPT_FREEBSD4 */ 855 856 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 857 #ifndef _SYS_SYSPROTO_H_ 858 struct osigaction_args { 859 int signum; 860 struct osigaction *nsa; 861 struct osigaction *osa; 862 }; 863 #endif 864 int 865 osigaction(td, uap) 866 struct thread *td; 867 register struct osigaction_args *uap; 868 { 869 struct osigaction sa; 870 struct sigaction nsa, osa; 871 register struct sigaction *nsap, *osap; 872 int error; 873 874 if (uap->signum <= 0 || uap->signum >= ONSIG) 875 return (EINVAL); 876 877 nsap = (uap->nsa != NULL) ? &nsa : NULL; 878 osap = (uap->osa != NULL) ? &osa : NULL; 879 880 if (nsap) { 881 error = copyin(uap->nsa, &sa, sizeof(sa)); 882 if (error) 883 return (error); 884 nsap->sa_handler = sa.sa_handler; 885 nsap->sa_flags = sa.sa_flags; 886 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 887 } 888 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 889 if (osap && !error) { 890 sa.sa_handler = osap->sa_handler; 891 sa.sa_flags = osap->sa_flags; 892 SIG2OSIG(osap->sa_mask, sa.sa_mask); 893 error = copyout(&sa, uap->osa, sizeof(sa)); 894 } 895 return (error); 896 } 897 898 #if !defined(__i386__) 899 /* Avoid replicating the same stub everywhere */ 900 int 901 osigreturn(td, uap) 902 struct thread *td; 903 struct osigreturn_args *uap; 904 { 905 906 return (nosys(td, (struct nosys_args *)uap)); 907 } 908 #endif 909 #endif /* COMPAT_43 */ 910 911 /* 912 * Initialize signal state for process 0; 913 * set to ignore signals that are ignored by default. 914 */ 915 void 916 siginit(p) 917 struct proc *p; 918 { 919 register int i; 920 struct sigacts *ps; 921 922 PROC_LOCK(p); 923 ps = p->p_sigacts; 924 mtx_lock(&ps->ps_mtx); 925 for (i = 1; i <= NSIG; i++) { 926 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 927 SIGADDSET(ps->ps_sigignore, i); 928 } 929 } 930 mtx_unlock(&ps->ps_mtx); 931 PROC_UNLOCK(p); 932 } 933 934 /* 935 * Reset specified signal to the default disposition. 936 */ 937 static void 938 sigdflt(struct sigacts *ps, int sig) 939 { 940 941 mtx_assert(&ps->ps_mtx, MA_OWNED); 942 SIGDELSET(ps->ps_sigcatch, sig); 943 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 944 SIGADDSET(ps->ps_sigignore, sig); 945 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 946 SIGDELSET(ps->ps_siginfo, sig); 947 } 948 949 /* 950 * Reset signals for an exec of the specified process. 951 */ 952 void 953 execsigs(struct proc *p) 954 { 955 struct sigacts *ps; 956 int sig; 957 struct thread *td; 958 959 /* 960 * Reset caught signals. Held signals remain held 961 * through td_sigmask (unless they were caught, 962 * and are now ignored by default). 963 */ 964 PROC_LOCK_ASSERT(p, MA_OWNED); 965 td = FIRST_THREAD_IN_PROC(p); 966 ps = p->p_sigacts; 967 mtx_lock(&ps->ps_mtx); 968 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 969 sig = sig_ffs(&ps->ps_sigcatch); 970 sigdflt(ps, sig); 971 if ((sigprop(sig) & SA_IGNORE) != 0) 972 sigqueue_delete_proc(p, sig); 973 } 974 /* 975 * Reset stack state to the user stack. 976 * Clear set of signals caught on the signal stack. 977 */ 978 td->td_sigstk.ss_flags = SS_DISABLE; 979 td->td_sigstk.ss_size = 0; 980 td->td_sigstk.ss_sp = 0; 981 td->td_pflags &= ~TDP_ALTSTACK; 982 /* 983 * Reset no zombies if child dies flag as Solaris does. 984 */ 985 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 986 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 987 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 988 mtx_unlock(&ps->ps_mtx); 989 } 990 991 /* 992 * kern_sigprocmask() 993 * 994 * Manipulate signal mask. 995 */ 996 int 997 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 998 int flags) 999 { 1000 sigset_t new_block, oset1; 1001 struct proc *p; 1002 int error; 1003 1004 p = td->td_proc; 1005 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1006 PROC_LOCK_ASSERT(p, MA_OWNED); 1007 else 1008 PROC_LOCK(p); 1009 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1010 ? MA_OWNED : MA_NOTOWNED); 1011 if (oset != NULL) 1012 *oset = td->td_sigmask; 1013 1014 error = 0; 1015 if (set != NULL) { 1016 switch (how) { 1017 case SIG_BLOCK: 1018 SIG_CANTMASK(*set); 1019 oset1 = td->td_sigmask; 1020 SIGSETOR(td->td_sigmask, *set); 1021 new_block = td->td_sigmask; 1022 SIGSETNAND(new_block, oset1); 1023 break; 1024 case SIG_UNBLOCK: 1025 SIGSETNAND(td->td_sigmask, *set); 1026 signotify(td); 1027 goto out; 1028 case SIG_SETMASK: 1029 SIG_CANTMASK(*set); 1030 oset1 = td->td_sigmask; 1031 if (flags & SIGPROCMASK_OLD) 1032 SIGSETLO(td->td_sigmask, *set); 1033 else 1034 td->td_sigmask = *set; 1035 new_block = td->td_sigmask; 1036 SIGSETNAND(new_block, oset1); 1037 signotify(td); 1038 break; 1039 default: 1040 error = EINVAL; 1041 goto out; 1042 } 1043 1044 /* 1045 * The new_block set contains signals that were not previously 1046 * blocked, but are blocked now. 1047 * 1048 * In case we block any signal that was not previously blocked 1049 * for td, and process has the signal pending, try to schedule 1050 * signal delivery to some thread that does not block the 1051 * signal, possibly waking it up. 1052 */ 1053 if (p->p_numthreads != 1) 1054 reschedule_signals(p, new_block, flags); 1055 } 1056 1057 out: 1058 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1059 PROC_UNLOCK(p); 1060 return (error); 1061 } 1062 1063 #ifndef _SYS_SYSPROTO_H_ 1064 struct sigprocmask_args { 1065 int how; 1066 const sigset_t *set; 1067 sigset_t *oset; 1068 }; 1069 #endif 1070 int 1071 sys_sigprocmask(td, uap) 1072 register struct thread *td; 1073 struct sigprocmask_args *uap; 1074 { 1075 sigset_t set, oset; 1076 sigset_t *setp, *osetp; 1077 int error; 1078 1079 setp = (uap->set != NULL) ? &set : NULL; 1080 osetp = (uap->oset != NULL) ? &oset : NULL; 1081 if (setp) { 1082 error = copyin(uap->set, setp, sizeof(set)); 1083 if (error) 1084 return (error); 1085 } 1086 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1087 if (osetp && !error) { 1088 error = copyout(osetp, uap->oset, sizeof(oset)); 1089 } 1090 return (error); 1091 } 1092 1093 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1094 #ifndef _SYS_SYSPROTO_H_ 1095 struct osigprocmask_args { 1096 int how; 1097 osigset_t mask; 1098 }; 1099 #endif 1100 int 1101 osigprocmask(td, uap) 1102 register struct thread *td; 1103 struct osigprocmask_args *uap; 1104 { 1105 sigset_t set, oset; 1106 int error; 1107 1108 OSIG2SIG(uap->mask, set); 1109 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1110 SIG2OSIG(oset, td->td_retval[0]); 1111 return (error); 1112 } 1113 #endif /* COMPAT_43 */ 1114 1115 int 1116 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1117 { 1118 ksiginfo_t ksi; 1119 sigset_t set; 1120 int error; 1121 1122 error = copyin(uap->set, &set, sizeof(set)); 1123 if (error) { 1124 td->td_retval[0] = error; 1125 return (0); 1126 } 1127 1128 error = kern_sigtimedwait(td, set, &ksi, NULL); 1129 if (error) { 1130 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1131 error = ERESTART; 1132 if (error == ERESTART) 1133 return (error); 1134 td->td_retval[0] = error; 1135 return (0); 1136 } 1137 1138 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1139 td->td_retval[0] = error; 1140 return (0); 1141 } 1142 1143 int 1144 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1145 { 1146 struct timespec ts; 1147 struct timespec *timeout; 1148 sigset_t set; 1149 ksiginfo_t ksi; 1150 int error; 1151 1152 if (uap->timeout) { 1153 error = copyin(uap->timeout, &ts, sizeof(ts)); 1154 if (error) 1155 return (error); 1156 1157 timeout = &ts; 1158 } else 1159 timeout = NULL; 1160 1161 error = copyin(uap->set, &set, sizeof(set)); 1162 if (error) 1163 return (error); 1164 1165 error = kern_sigtimedwait(td, set, &ksi, timeout); 1166 if (error) 1167 return (error); 1168 1169 if (uap->info) 1170 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1171 1172 if (error == 0) 1173 td->td_retval[0] = ksi.ksi_signo; 1174 return (error); 1175 } 1176 1177 int 1178 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1179 { 1180 ksiginfo_t ksi; 1181 sigset_t set; 1182 int error; 1183 1184 error = copyin(uap->set, &set, sizeof(set)); 1185 if (error) 1186 return (error); 1187 1188 error = kern_sigtimedwait(td, set, &ksi, NULL); 1189 if (error) 1190 return (error); 1191 1192 if (uap->info) 1193 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1194 1195 if (error == 0) 1196 td->td_retval[0] = ksi.ksi_signo; 1197 return (error); 1198 } 1199 1200 int 1201 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1202 struct timespec *timeout) 1203 { 1204 struct sigacts *ps; 1205 sigset_t saved_mask, new_block; 1206 struct proc *p; 1207 int error, sig, timo, timevalid = 0; 1208 struct timespec rts, ets, ts; 1209 struct timeval tv; 1210 1211 p = td->td_proc; 1212 error = 0; 1213 ets.tv_sec = 0; 1214 ets.tv_nsec = 0; 1215 1216 if (timeout != NULL) { 1217 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1218 timevalid = 1; 1219 getnanouptime(&rts); 1220 ets = rts; 1221 timespecadd(&ets, timeout); 1222 } 1223 } 1224 ksiginfo_init(ksi); 1225 /* Some signals can not be waited for. */ 1226 SIG_CANTMASK(waitset); 1227 ps = p->p_sigacts; 1228 PROC_LOCK(p); 1229 saved_mask = td->td_sigmask; 1230 SIGSETNAND(td->td_sigmask, waitset); 1231 for (;;) { 1232 mtx_lock(&ps->ps_mtx); 1233 sig = cursig(td); 1234 mtx_unlock(&ps->ps_mtx); 1235 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1236 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1237 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1238 error = 0; 1239 break; 1240 } 1241 } 1242 1243 if (error != 0) 1244 break; 1245 1246 /* 1247 * POSIX says this must be checked after looking for pending 1248 * signals. 1249 */ 1250 if (timeout != NULL) { 1251 if (!timevalid) { 1252 error = EINVAL; 1253 break; 1254 } 1255 getnanouptime(&rts); 1256 if (timespeccmp(&rts, &ets, >=)) { 1257 error = EAGAIN; 1258 break; 1259 } 1260 ts = ets; 1261 timespecsub(&ts, &rts); 1262 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1263 timo = tvtohz(&tv); 1264 } else { 1265 timo = 0; 1266 } 1267 1268 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1269 1270 if (timeout != NULL) { 1271 if (error == ERESTART) { 1272 /* Timeout can not be restarted. */ 1273 error = EINTR; 1274 } else if (error == EAGAIN) { 1275 /* We will calculate timeout by ourself. */ 1276 error = 0; 1277 } 1278 } 1279 } 1280 1281 new_block = saved_mask; 1282 SIGSETNAND(new_block, td->td_sigmask); 1283 td->td_sigmask = saved_mask; 1284 /* 1285 * Fewer signals can be delivered to us, reschedule signal 1286 * notification. 1287 */ 1288 if (p->p_numthreads != 1) 1289 reschedule_signals(p, new_block, 0); 1290 1291 if (error == 0) { 1292 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0); 1293 1294 if (ksi->ksi_code == SI_TIMER) 1295 itimer_accept(p, ksi->ksi_timerid, ksi); 1296 1297 #ifdef KTRACE 1298 if (KTRPOINT(td, KTR_PSIG)) { 1299 sig_t action; 1300 1301 mtx_lock(&ps->ps_mtx); 1302 action = ps->ps_sigact[_SIG_IDX(sig)]; 1303 mtx_unlock(&ps->ps_mtx); 1304 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1305 } 1306 #endif 1307 if (sig == SIGKILL) 1308 sigexit(td, sig); 1309 } 1310 PROC_UNLOCK(p); 1311 return (error); 1312 } 1313 1314 #ifndef _SYS_SYSPROTO_H_ 1315 struct sigpending_args { 1316 sigset_t *set; 1317 }; 1318 #endif 1319 int 1320 sys_sigpending(td, uap) 1321 struct thread *td; 1322 struct sigpending_args *uap; 1323 { 1324 struct proc *p = td->td_proc; 1325 sigset_t pending; 1326 1327 PROC_LOCK(p); 1328 pending = p->p_sigqueue.sq_signals; 1329 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1330 PROC_UNLOCK(p); 1331 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1332 } 1333 1334 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1335 #ifndef _SYS_SYSPROTO_H_ 1336 struct osigpending_args { 1337 int dummy; 1338 }; 1339 #endif 1340 int 1341 osigpending(td, uap) 1342 struct thread *td; 1343 struct osigpending_args *uap; 1344 { 1345 struct proc *p = td->td_proc; 1346 sigset_t pending; 1347 1348 PROC_LOCK(p); 1349 pending = p->p_sigqueue.sq_signals; 1350 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1351 PROC_UNLOCK(p); 1352 SIG2OSIG(pending, td->td_retval[0]); 1353 return (0); 1354 } 1355 #endif /* COMPAT_43 */ 1356 1357 #if defined(COMPAT_43) 1358 /* 1359 * Generalized interface signal handler, 4.3-compatible. 1360 */ 1361 #ifndef _SYS_SYSPROTO_H_ 1362 struct osigvec_args { 1363 int signum; 1364 struct sigvec *nsv; 1365 struct sigvec *osv; 1366 }; 1367 #endif 1368 /* ARGSUSED */ 1369 int 1370 osigvec(td, uap) 1371 struct thread *td; 1372 register struct osigvec_args *uap; 1373 { 1374 struct sigvec vec; 1375 struct sigaction nsa, osa; 1376 register struct sigaction *nsap, *osap; 1377 int error; 1378 1379 if (uap->signum <= 0 || uap->signum >= ONSIG) 1380 return (EINVAL); 1381 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1382 osap = (uap->osv != NULL) ? &osa : NULL; 1383 if (nsap) { 1384 error = copyin(uap->nsv, &vec, sizeof(vec)); 1385 if (error) 1386 return (error); 1387 nsap->sa_handler = vec.sv_handler; 1388 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1389 nsap->sa_flags = vec.sv_flags; 1390 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1391 } 1392 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1393 if (osap && !error) { 1394 vec.sv_handler = osap->sa_handler; 1395 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1396 vec.sv_flags = osap->sa_flags; 1397 vec.sv_flags &= ~SA_NOCLDWAIT; 1398 vec.sv_flags ^= SA_RESTART; 1399 error = copyout(&vec, uap->osv, sizeof(vec)); 1400 } 1401 return (error); 1402 } 1403 1404 #ifndef _SYS_SYSPROTO_H_ 1405 struct osigblock_args { 1406 int mask; 1407 }; 1408 #endif 1409 int 1410 osigblock(td, uap) 1411 register struct thread *td; 1412 struct osigblock_args *uap; 1413 { 1414 sigset_t set, oset; 1415 1416 OSIG2SIG(uap->mask, set); 1417 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1418 SIG2OSIG(oset, td->td_retval[0]); 1419 return (0); 1420 } 1421 1422 #ifndef _SYS_SYSPROTO_H_ 1423 struct osigsetmask_args { 1424 int mask; 1425 }; 1426 #endif 1427 int 1428 osigsetmask(td, uap) 1429 struct thread *td; 1430 struct osigsetmask_args *uap; 1431 { 1432 sigset_t set, oset; 1433 1434 OSIG2SIG(uap->mask, set); 1435 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1436 SIG2OSIG(oset, td->td_retval[0]); 1437 return (0); 1438 } 1439 #endif /* COMPAT_43 */ 1440 1441 /* 1442 * Suspend calling thread until signal, providing mask to be set in the 1443 * meantime. 1444 */ 1445 #ifndef _SYS_SYSPROTO_H_ 1446 struct sigsuspend_args { 1447 const sigset_t *sigmask; 1448 }; 1449 #endif 1450 /* ARGSUSED */ 1451 int 1452 sys_sigsuspend(td, uap) 1453 struct thread *td; 1454 struct sigsuspend_args *uap; 1455 { 1456 sigset_t mask; 1457 int error; 1458 1459 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1460 if (error) 1461 return (error); 1462 return (kern_sigsuspend(td, mask)); 1463 } 1464 1465 int 1466 kern_sigsuspend(struct thread *td, sigset_t mask) 1467 { 1468 struct proc *p = td->td_proc; 1469 int has_sig, sig; 1470 1471 /* 1472 * When returning from sigsuspend, we want 1473 * the old mask to be restored after the 1474 * signal handler has finished. Thus, we 1475 * save it here and mark the sigacts structure 1476 * to indicate this. 1477 */ 1478 PROC_LOCK(p); 1479 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1480 SIGPROCMASK_PROC_LOCKED); 1481 td->td_pflags |= TDP_OLDMASK; 1482 1483 /* 1484 * Process signals now. Otherwise, we can get spurious wakeup 1485 * due to signal entered process queue, but delivered to other 1486 * thread. But sigsuspend should return only on signal 1487 * delivery. 1488 */ 1489 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1490 for (has_sig = 0; !has_sig;) { 1491 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1492 0) == 0) 1493 /* void */; 1494 thread_suspend_check(0); 1495 mtx_lock(&p->p_sigacts->ps_mtx); 1496 while ((sig = cursig(td)) != 0) 1497 has_sig += postsig(sig); 1498 mtx_unlock(&p->p_sigacts->ps_mtx); 1499 } 1500 PROC_UNLOCK(p); 1501 td->td_errno = EINTR; 1502 td->td_pflags |= TDP_NERRNO; 1503 return (EJUSTRETURN); 1504 } 1505 1506 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1507 /* 1508 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1509 * convention: libc stub passes mask, not pointer, to save a copyin. 1510 */ 1511 #ifndef _SYS_SYSPROTO_H_ 1512 struct osigsuspend_args { 1513 osigset_t mask; 1514 }; 1515 #endif 1516 /* ARGSUSED */ 1517 int 1518 osigsuspend(td, uap) 1519 struct thread *td; 1520 struct osigsuspend_args *uap; 1521 { 1522 sigset_t mask; 1523 1524 OSIG2SIG(uap->mask, mask); 1525 return (kern_sigsuspend(td, mask)); 1526 } 1527 #endif /* COMPAT_43 */ 1528 1529 #if defined(COMPAT_43) 1530 #ifndef _SYS_SYSPROTO_H_ 1531 struct osigstack_args { 1532 struct sigstack *nss; 1533 struct sigstack *oss; 1534 }; 1535 #endif 1536 /* ARGSUSED */ 1537 int 1538 osigstack(td, uap) 1539 struct thread *td; 1540 register struct osigstack_args *uap; 1541 { 1542 struct sigstack nss, oss; 1543 int error = 0; 1544 1545 if (uap->nss != NULL) { 1546 error = copyin(uap->nss, &nss, sizeof(nss)); 1547 if (error) 1548 return (error); 1549 } 1550 oss.ss_sp = td->td_sigstk.ss_sp; 1551 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1552 if (uap->nss != NULL) { 1553 td->td_sigstk.ss_sp = nss.ss_sp; 1554 td->td_sigstk.ss_size = 0; 1555 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1556 td->td_pflags |= TDP_ALTSTACK; 1557 } 1558 if (uap->oss != NULL) 1559 error = copyout(&oss, uap->oss, sizeof(oss)); 1560 1561 return (error); 1562 } 1563 #endif /* COMPAT_43 */ 1564 1565 #ifndef _SYS_SYSPROTO_H_ 1566 struct sigaltstack_args { 1567 stack_t *ss; 1568 stack_t *oss; 1569 }; 1570 #endif 1571 /* ARGSUSED */ 1572 int 1573 sys_sigaltstack(td, uap) 1574 struct thread *td; 1575 register struct sigaltstack_args *uap; 1576 { 1577 stack_t ss, oss; 1578 int error; 1579 1580 if (uap->ss != NULL) { 1581 error = copyin(uap->ss, &ss, sizeof(ss)); 1582 if (error) 1583 return (error); 1584 } 1585 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1586 (uap->oss != NULL) ? &oss : NULL); 1587 if (error) 1588 return (error); 1589 if (uap->oss != NULL) 1590 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1591 return (error); 1592 } 1593 1594 int 1595 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1596 { 1597 struct proc *p = td->td_proc; 1598 int oonstack; 1599 1600 oonstack = sigonstack(cpu_getstack(td)); 1601 1602 if (oss != NULL) { 1603 *oss = td->td_sigstk; 1604 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1605 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1606 } 1607 1608 if (ss != NULL) { 1609 if (oonstack) 1610 return (EPERM); 1611 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1612 return (EINVAL); 1613 if (!(ss->ss_flags & SS_DISABLE)) { 1614 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1615 return (ENOMEM); 1616 1617 td->td_sigstk = *ss; 1618 td->td_pflags |= TDP_ALTSTACK; 1619 } else { 1620 td->td_pflags &= ~TDP_ALTSTACK; 1621 } 1622 } 1623 return (0); 1624 } 1625 1626 /* 1627 * Common code for kill process group/broadcast kill. 1628 * cp is calling process. 1629 */ 1630 static int 1631 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1632 { 1633 struct proc *p; 1634 struct pgrp *pgrp; 1635 int err; 1636 int ret; 1637 1638 ret = ESRCH; 1639 if (all) { 1640 /* 1641 * broadcast 1642 */ 1643 sx_slock(&allproc_lock); 1644 FOREACH_PROC_IN_SYSTEM(p) { 1645 PROC_LOCK(p); 1646 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1647 p == td->td_proc || p->p_state == PRS_NEW) { 1648 PROC_UNLOCK(p); 1649 continue; 1650 } 1651 err = p_cansignal(td, p, sig); 1652 if (err == 0) { 1653 if (sig) 1654 pksignal(p, sig, ksi); 1655 ret = err; 1656 } 1657 else if (ret == ESRCH) 1658 ret = err; 1659 PROC_UNLOCK(p); 1660 } 1661 sx_sunlock(&allproc_lock); 1662 } else { 1663 sx_slock(&proctree_lock); 1664 if (pgid == 0) { 1665 /* 1666 * zero pgid means send to my process group. 1667 */ 1668 pgrp = td->td_proc->p_pgrp; 1669 PGRP_LOCK(pgrp); 1670 } else { 1671 pgrp = pgfind(pgid); 1672 if (pgrp == NULL) { 1673 sx_sunlock(&proctree_lock); 1674 return (ESRCH); 1675 } 1676 } 1677 sx_sunlock(&proctree_lock); 1678 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1679 PROC_LOCK(p); 1680 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1681 p->p_state == PRS_NEW) { 1682 PROC_UNLOCK(p); 1683 continue; 1684 } 1685 err = p_cansignal(td, p, sig); 1686 if (err == 0) { 1687 if (sig) 1688 pksignal(p, sig, ksi); 1689 ret = err; 1690 } 1691 else if (ret == ESRCH) 1692 ret = err; 1693 PROC_UNLOCK(p); 1694 } 1695 PGRP_UNLOCK(pgrp); 1696 } 1697 return (ret); 1698 } 1699 1700 #ifndef _SYS_SYSPROTO_H_ 1701 struct kill_args { 1702 int pid; 1703 int signum; 1704 }; 1705 #endif 1706 /* ARGSUSED */ 1707 int 1708 sys_kill(struct thread *td, struct kill_args *uap) 1709 { 1710 ksiginfo_t ksi; 1711 struct proc *p; 1712 int error; 1713 1714 /* 1715 * A process in capability mode can send signals only to himself. 1716 * The main rationale behind this is that abort(3) is implemented as 1717 * kill(getpid(), SIGABRT). 1718 */ 1719 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1720 return (ECAPMODE); 1721 1722 AUDIT_ARG_SIGNUM(uap->signum); 1723 AUDIT_ARG_PID(uap->pid); 1724 if ((u_int)uap->signum > _SIG_MAXSIG) 1725 return (EINVAL); 1726 1727 ksiginfo_init(&ksi); 1728 ksi.ksi_signo = uap->signum; 1729 ksi.ksi_code = SI_USER; 1730 ksi.ksi_pid = td->td_proc->p_pid; 1731 ksi.ksi_uid = td->td_ucred->cr_ruid; 1732 1733 if (uap->pid > 0) { 1734 /* kill single process */ 1735 if ((p = pfind(uap->pid)) == NULL) { 1736 if ((p = zpfind(uap->pid)) == NULL) 1737 return (ESRCH); 1738 } 1739 AUDIT_ARG_PROCESS(p); 1740 error = p_cansignal(td, p, uap->signum); 1741 if (error == 0 && uap->signum) 1742 pksignal(p, uap->signum, &ksi); 1743 PROC_UNLOCK(p); 1744 return (error); 1745 } 1746 switch (uap->pid) { 1747 case -1: /* broadcast signal */ 1748 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1749 case 0: /* signal own process group */ 1750 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1751 default: /* negative explicit process group */ 1752 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1753 } 1754 /* NOTREACHED */ 1755 } 1756 1757 int 1758 sys_pdkill(td, uap) 1759 struct thread *td; 1760 struct pdkill_args *uap; 1761 { 1762 struct proc *p; 1763 cap_rights_t rights; 1764 int error; 1765 1766 AUDIT_ARG_SIGNUM(uap->signum); 1767 AUDIT_ARG_FD(uap->fd); 1768 if ((u_int)uap->signum > _SIG_MAXSIG) 1769 return (EINVAL); 1770 1771 error = procdesc_find(td, uap->fd, 1772 cap_rights_init(&rights, CAP_PDKILL), &p); 1773 if (error) 1774 return (error); 1775 AUDIT_ARG_PROCESS(p); 1776 error = p_cansignal(td, p, uap->signum); 1777 if (error == 0 && uap->signum) 1778 kern_psignal(p, uap->signum); 1779 PROC_UNLOCK(p); 1780 return (error); 1781 } 1782 1783 #if defined(COMPAT_43) 1784 #ifndef _SYS_SYSPROTO_H_ 1785 struct okillpg_args { 1786 int pgid; 1787 int signum; 1788 }; 1789 #endif 1790 /* ARGSUSED */ 1791 int 1792 okillpg(struct thread *td, struct okillpg_args *uap) 1793 { 1794 ksiginfo_t ksi; 1795 1796 AUDIT_ARG_SIGNUM(uap->signum); 1797 AUDIT_ARG_PID(uap->pgid); 1798 if ((u_int)uap->signum > _SIG_MAXSIG) 1799 return (EINVAL); 1800 1801 ksiginfo_init(&ksi); 1802 ksi.ksi_signo = uap->signum; 1803 ksi.ksi_code = SI_USER; 1804 ksi.ksi_pid = td->td_proc->p_pid; 1805 ksi.ksi_uid = td->td_ucred->cr_ruid; 1806 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1807 } 1808 #endif /* COMPAT_43 */ 1809 1810 #ifndef _SYS_SYSPROTO_H_ 1811 struct sigqueue_args { 1812 pid_t pid; 1813 int signum; 1814 /* union sigval */ void *value; 1815 }; 1816 #endif 1817 int 1818 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1819 { 1820 ksiginfo_t ksi; 1821 struct proc *p; 1822 int error; 1823 1824 if ((u_int)uap->signum > _SIG_MAXSIG) 1825 return (EINVAL); 1826 1827 /* 1828 * Specification says sigqueue can only send signal to 1829 * single process. 1830 */ 1831 if (uap->pid <= 0) 1832 return (EINVAL); 1833 1834 if ((p = pfind(uap->pid)) == NULL) { 1835 if ((p = zpfind(uap->pid)) == NULL) 1836 return (ESRCH); 1837 } 1838 error = p_cansignal(td, p, uap->signum); 1839 if (error == 0 && uap->signum != 0) { 1840 ksiginfo_init(&ksi); 1841 ksi.ksi_flags = KSI_SIGQ; 1842 ksi.ksi_signo = uap->signum; 1843 ksi.ksi_code = SI_QUEUE; 1844 ksi.ksi_pid = td->td_proc->p_pid; 1845 ksi.ksi_uid = td->td_ucred->cr_ruid; 1846 ksi.ksi_value.sival_ptr = uap->value; 1847 error = pksignal(p, ksi.ksi_signo, &ksi); 1848 } 1849 PROC_UNLOCK(p); 1850 return (error); 1851 } 1852 1853 /* 1854 * Send a signal to a process group. 1855 */ 1856 void 1857 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1858 { 1859 struct pgrp *pgrp; 1860 1861 if (pgid != 0) { 1862 sx_slock(&proctree_lock); 1863 pgrp = pgfind(pgid); 1864 sx_sunlock(&proctree_lock); 1865 if (pgrp != NULL) { 1866 pgsignal(pgrp, sig, 0, ksi); 1867 PGRP_UNLOCK(pgrp); 1868 } 1869 } 1870 } 1871 1872 /* 1873 * Send a signal to a process group. If checktty is 1, 1874 * limit to members which have a controlling terminal. 1875 */ 1876 void 1877 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1878 { 1879 struct proc *p; 1880 1881 if (pgrp) { 1882 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1883 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1884 PROC_LOCK(p); 1885 if (p->p_state == PRS_NORMAL && 1886 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1887 pksignal(p, sig, ksi); 1888 PROC_UNLOCK(p); 1889 } 1890 } 1891 } 1892 1893 1894 /* 1895 * Recalculate the signal mask and reset the signal disposition after 1896 * usermode frame for delivery is formed. Should be called after 1897 * mach-specific routine, because sysent->sv_sendsig() needs correct 1898 * ps_siginfo and signal mask. 1899 */ 1900 static void 1901 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1902 { 1903 sigset_t mask; 1904 1905 mtx_assert(&ps->ps_mtx, MA_OWNED); 1906 td->td_ru.ru_nsignals++; 1907 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1908 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1909 SIGADDSET(mask, sig); 1910 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1911 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1912 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1913 sigdflt(ps, sig); 1914 } 1915 1916 1917 /* 1918 * Send a signal caused by a trap to the current thread. If it will be 1919 * caught immediately, deliver it with correct code. Otherwise, post it 1920 * normally. 1921 */ 1922 void 1923 trapsignal(struct thread *td, ksiginfo_t *ksi) 1924 { 1925 struct sigacts *ps; 1926 struct proc *p; 1927 int sig; 1928 int code; 1929 1930 p = td->td_proc; 1931 sig = ksi->ksi_signo; 1932 code = ksi->ksi_code; 1933 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1934 1935 PROC_LOCK(p); 1936 ps = p->p_sigacts; 1937 mtx_lock(&ps->ps_mtx); 1938 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1939 !SIGISMEMBER(td->td_sigmask, sig)) { 1940 #ifdef KTRACE 1941 if (KTRPOINT(curthread, KTR_PSIG)) 1942 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1943 &td->td_sigmask, code); 1944 #endif 1945 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1946 ksi, &td->td_sigmask); 1947 postsig_done(sig, td, ps); 1948 mtx_unlock(&ps->ps_mtx); 1949 } else { 1950 /* 1951 * Avoid a possible infinite loop if the thread 1952 * masking the signal or process is ignoring the 1953 * signal. 1954 */ 1955 if (kern_forcesigexit && 1956 (SIGISMEMBER(td->td_sigmask, sig) || 1957 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1958 SIGDELSET(td->td_sigmask, sig); 1959 SIGDELSET(ps->ps_sigcatch, sig); 1960 SIGDELSET(ps->ps_sigignore, sig); 1961 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1962 } 1963 mtx_unlock(&ps->ps_mtx); 1964 p->p_code = code; /* XXX for core dump/debugger */ 1965 p->p_sig = sig; /* XXX to verify code */ 1966 tdsendsignal(p, td, sig, ksi); 1967 } 1968 PROC_UNLOCK(p); 1969 } 1970 1971 static struct thread * 1972 sigtd(struct proc *p, int sig, int prop) 1973 { 1974 struct thread *td, *signal_td; 1975 1976 PROC_LOCK_ASSERT(p, MA_OWNED); 1977 1978 /* 1979 * Check if current thread can handle the signal without 1980 * switching context to another thread. 1981 */ 1982 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1983 return (curthread); 1984 signal_td = NULL; 1985 FOREACH_THREAD_IN_PROC(p, td) { 1986 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1987 signal_td = td; 1988 break; 1989 } 1990 } 1991 if (signal_td == NULL) 1992 signal_td = FIRST_THREAD_IN_PROC(p); 1993 return (signal_td); 1994 } 1995 1996 /* 1997 * Send the signal to the process. If the signal has an action, the action 1998 * is usually performed by the target process rather than the caller; we add 1999 * the signal to the set of pending signals for the process. 2000 * 2001 * Exceptions: 2002 * o When a stop signal is sent to a sleeping process that takes the 2003 * default action, the process is stopped without awakening it. 2004 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2005 * regardless of the signal action (eg, blocked or ignored). 2006 * 2007 * Other ignored signals are discarded immediately. 2008 * 2009 * NB: This function may be entered from the debugger via the "kill" DDB 2010 * command. There is little that can be done to mitigate the possibly messy 2011 * side effects of this unwise possibility. 2012 */ 2013 void 2014 kern_psignal(struct proc *p, int sig) 2015 { 2016 ksiginfo_t ksi; 2017 2018 ksiginfo_init(&ksi); 2019 ksi.ksi_signo = sig; 2020 ksi.ksi_code = SI_KERNEL; 2021 (void) tdsendsignal(p, NULL, sig, &ksi); 2022 } 2023 2024 int 2025 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2026 { 2027 2028 return (tdsendsignal(p, NULL, sig, ksi)); 2029 } 2030 2031 /* Utility function for finding a thread to send signal event to. */ 2032 int 2033 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2034 { 2035 struct thread *td; 2036 2037 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2038 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2039 if (td == NULL) 2040 return (ESRCH); 2041 *ttd = td; 2042 } else { 2043 *ttd = NULL; 2044 PROC_LOCK(p); 2045 } 2046 return (0); 2047 } 2048 2049 void 2050 tdsignal(struct thread *td, int sig) 2051 { 2052 ksiginfo_t ksi; 2053 2054 ksiginfo_init(&ksi); 2055 ksi.ksi_signo = sig; 2056 ksi.ksi_code = SI_KERNEL; 2057 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2058 } 2059 2060 void 2061 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2062 { 2063 2064 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2065 } 2066 2067 int 2068 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2069 { 2070 sig_t action; 2071 sigqueue_t *sigqueue; 2072 int prop; 2073 struct sigacts *ps; 2074 int intrval; 2075 int ret = 0; 2076 int wakeup_swapper; 2077 2078 MPASS(td == NULL || p == td->td_proc); 2079 PROC_LOCK_ASSERT(p, MA_OWNED); 2080 2081 if (!_SIG_VALID(sig)) 2082 panic("%s(): invalid signal %d", __func__, sig); 2083 2084 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2085 2086 /* 2087 * IEEE Std 1003.1-2001: return success when killing a zombie. 2088 */ 2089 if (p->p_state == PRS_ZOMBIE) { 2090 if (ksi && (ksi->ksi_flags & KSI_INS)) 2091 ksiginfo_tryfree(ksi); 2092 return (ret); 2093 } 2094 2095 ps = p->p_sigacts; 2096 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2097 prop = sigprop(sig); 2098 2099 if (td == NULL) { 2100 td = sigtd(p, sig, prop); 2101 sigqueue = &p->p_sigqueue; 2102 } else 2103 sigqueue = &td->td_sigqueue; 2104 2105 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 ); 2106 2107 /* 2108 * If the signal is being ignored, 2109 * then we forget about it immediately. 2110 * (Note: we don't set SIGCONT in ps_sigignore, 2111 * and if it is set to SIG_IGN, 2112 * action will be SIG_DFL here.) 2113 */ 2114 mtx_lock(&ps->ps_mtx); 2115 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2116 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 ); 2117 2118 mtx_unlock(&ps->ps_mtx); 2119 if (ksi && (ksi->ksi_flags & KSI_INS)) 2120 ksiginfo_tryfree(ksi); 2121 return (ret); 2122 } 2123 if (SIGISMEMBER(td->td_sigmask, sig)) 2124 action = SIG_HOLD; 2125 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2126 action = SIG_CATCH; 2127 else 2128 action = SIG_DFL; 2129 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2130 intrval = EINTR; 2131 else 2132 intrval = ERESTART; 2133 mtx_unlock(&ps->ps_mtx); 2134 2135 if (prop & SA_CONT) 2136 sigqueue_delete_stopmask_proc(p); 2137 else if (prop & SA_STOP) { 2138 /* 2139 * If sending a tty stop signal to a member of an orphaned 2140 * process group, discard the signal here if the action 2141 * is default; don't stop the process below if sleeping, 2142 * and don't clear any pending SIGCONT. 2143 */ 2144 if ((prop & SA_TTYSTOP) && 2145 (p->p_pgrp->pg_jobc == 0) && 2146 (action == SIG_DFL)) { 2147 if (ksi && (ksi->ksi_flags & KSI_INS)) 2148 ksiginfo_tryfree(ksi); 2149 return (ret); 2150 } 2151 sigqueue_delete_proc(p, SIGCONT); 2152 if (p->p_flag & P_CONTINUED) { 2153 p->p_flag &= ~P_CONTINUED; 2154 PROC_LOCK(p->p_pptr); 2155 sigqueue_take(p->p_ksi); 2156 PROC_UNLOCK(p->p_pptr); 2157 } 2158 } 2159 2160 ret = sigqueue_add(sigqueue, sig, ksi); 2161 if (ret != 0) 2162 return (ret); 2163 signotify(td); 2164 /* 2165 * Defer further processing for signals which are held, 2166 * except that stopped processes must be continued by SIGCONT. 2167 */ 2168 if (action == SIG_HOLD && 2169 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2170 return (ret); 2171 /* 2172 * SIGKILL: Remove procfs STOPEVENTs. 2173 */ 2174 if (sig == SIGKILL) { 2175 /* from procfs_ioctl.c: PIOCBIC */ 2176 p->p_stops = 0; 2177 /* from procfs_ioctl.c: PIOCCONT */ 2178 p->p_step = 0; 2179 wakeup(&p->p_step); 2180 } 2181 /* 2182 * Some signals have a process-wide effect and a per-thread 2183 * component. Most processing occurs when the process next 2184 * tries to cross the user boundary, however there are some 2185 * times when processing needs to be done immediately, such as 2186 * waking up threads so that they can cross the user boundary. 2187 * We try to do the per-process part here. 2188 */ 2189 if (P_SHOULDSTOP(p)) { 2190 KASSERT(!(p->p_flag & P_WEXIT), 2191 ("signal to stopped but exiting process")); 2192 if (sig == SIGKILL) { 2193 /* 2194 * If traced process is already stopped, 2195 * then no further action is necessary. 2196 */ 2197 if (p->p_flag & P_TRACED) 2198 goto out; 2199 /* 2200 * SIGKILL sets process running. 2201 * It will die elsewhere. 2202 * All threads must be restarted. 2203 */ 2204 p->p_flag &= ~P_STOPPED_SIG; 2205 goto runfast; 2206 } 2207 2208 if (prop & SA_CONT) { 2209 /* 2210 * If traced process is already stopped, 2211 * then no further action is necessary. 2212 */ 2213 if (p->p_flag & P_TRACED) 2214 goto out; 2215 /* 2216 * If SIGCONT is default (or ignored), we continue the 2217 * process but don't leave the signal in sigqueue as 2218 * it has no further action. If SIGCONT is held, we 2219 * continue the process and leave the signal in 2220 * sigqueue. If the process catches SIGCONT, let it 2221 * handle the signal itself. If it isn't waiting on 2222 * an event, it goes back to run state. 2223 * Otherwise, process goes back to sleep state. 2224 */ 2225 p->p_flag &= ~P_STOPPED_SIG; 2226 PROC_SLOCK(p); 2227 if (p->p_numthreads == p->p_suspcount) { 2228 PROC_SUNLOCK(p); 2229 p->p_flag |= P_CONTINUED; 2230 p->p_xsig = SIGCONT; 2231 PROC_LOCK(p->p_pptr); 2232 childproc_continued(p); 2233 PROC_UNLOCK(p->p_pptr); 2234 PROC_SLOCK(p); 2235 } 2236 if (action == SIG_DFL) { 2237 thread_unsuspend(p); 2238 PROC_SUNLOCK(p); 2239 sigqueue_delete(sigqueue, sig); 2240 goto out; 2241 } 2242 if (action == SIG_CATCH) { 2243 /* 2244 * The process wants to catch it so it needs 2245 * to run at least one thread, but which one? 2246 */ 2247 PROC_SUNLOCK(p); 2248 goto runfast; 2249 } 2250 /* 2251 * The signal is not ignored or caught. 2252 */ 2253 thread_unsuspend(p); 2254 PROC_SUNLOCK(p); 2255 goto out; 2256 } 2257 2258 if (prop & SA_STOP) { 2259 /* 2260 * If traced process is already stopped, 2261 * then no further action is necessary. 2262 */ 2263 if (p->p_flag & P_TRACED) 2264 goto out; 2265 /* 2266 * Already stopped, don't need to stop again 2267 * (If we did the shell could get confused). 2268 * Just make sure the signal STOP bit set. 2269 */ 2270 p->p_flag |= P_STOPPED_SIG; 2271 sigqueue_delete(sigqueue, sig); 2272 goto out; 2273 } 2274 2275 /* 2276 * All other kinds of signals: 2277 * If a thread is sleeping interruptibly, simulate a 2278 * wakeup so that when it is continued it will be made 2279 * runnable and can look at the signal. However, don't make 2280 * the PROCESS runnable, leave it stopped. 2281 * It may run a bit until it hits a thread_suspend_check(). 2282 */ 2283 wakeup_swapper = 0; 2284 PROC_SLOCK(p); 2285 thread_lock(td); 2286 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2287 wakeup_swapper = sleepq_abort(td, intrval); 2288 thread_unlock(td); 2289 PROC_SUNLOCK(p); 2290 if (wakeup_swapper) 2291 kick_proc0(); 2292 goto out; 2293 /* 2294 * Mutexes are short lived. Threads waiting on them will 2295 * hit thread_suspend_check() soon. 2296 */ 2297 } else if (p->p_state == PRS_NORMAL) { 2298 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2299 tdsigwakeup(td, sig, action, intrval); 2300 goto out; 2301 } 2302 2303 MPASS(action == SIG_DFL); 2304 2305 if (prop & SA_STOP) { 2306 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2307 goto out; 2308 p->p_flag |= P_STOPPED_SIG; 2309 p->p_xsig = sig; 2310 PROC_SLOCK(p); 2311 sig_suspend_threads(td, p, 1); 2312 if (p->p_numthreads == p->p_suspcount) { 2313 /* 2314 * only thread sending signal to another 2315 * process can reach here, if thread is sending 2316 * signal to its process, because thread does 2317 * not suspend itself here, p_numthreads 2318 * should never be equal to p_suspcount. 2319 */ 2320 thread_stopped(p); 2321 PROC_SUNLOCK(p); 2322 sigqueue_delete_proc(p, p->p_xsig); 2323 } else 2324 PROC_SUNLOCK(p); 2325 goto out; 2326 } 2327 } else { 2328 /* Not in "NORMAL" state. discard the signal. */ 2329 sigqueue_delete(sigqueue, sig); 2330 goto out; 2331 } 2332 2333 /* 2334 * The process is not stopped so we need to apply the signal to all the 2335 * running threads. 2336 */ 2337 runfast: 2338 tdsigwakeup(td, sig, action, intrval); 2339 PROC_SLOCK(p); 2340 thread_unsuspend(p); 2341 PROC_SUNLOCK(p); 2342 out: 2343 /* If we jump here, proc slock should not be owned. */ 2344 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2345 return (ret); 2346 } 2347 2348 /* 2349 * The force of a signal has been directed against a single 2350 * thread. We need to see what we can do about knocking it 2351 * out of any sleep it may be in etc. 2352 */ 2353 static void 2354 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2355 { 2356 struct proc *p = td->td_proc; 2357 register int prop; 2358 int wakeup_swapper; 2359 2360 wakeup_swapper = 0; 2361 PROC_LOCK_ASSERT(p, MA_OWNED); 2362 prop = sigprop(sig); 2363 2364 PROC_SLOCK(p); 2365 thread_lock(td); 2366 /* 2367 * Bring the priority of a thread up if we want it to get 2368 * killed in this lifetime. Be careful to avoid bumping the 2369 * priority of the idle thread, since we still allow to signal 2370 * kernel processes. 2371 */ 2372 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2373 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2374 sched_prio(td, PUSER); 2375 if (TD_ON_SLEEPQ(td)) { 2376 /* 2377 * If thread is sleeping uninterruptibly 2378 * we can't interrupt the sleep... the signal will 2379 * be noticed when the process returns through 2380 * trap() or syscall(). 2381 */ 2382 if ((td->td_flags & TDF_SINTR) == 0) 2383 goto out; 2384 /* 2385 * If SIGCONT is default (or ignored) and process is 2386 * asleep, we are finished; the process should not 2387 * be awakened. 2388 */ 2389 if ((prop & SA_CONT) && action == SIG_DFL) { 2390 thread_unlock(td); 2391 PROC_SUNLOCK(p); 2392 sigqueue_delete(&p->p_sigqueue, sig); 2393 /* 2394 * It may be on either list in this state. 2395 * Remove from both for now. 2396 */ 2397 sigqueue_delete(&td->td_sigqueue, sig); 2398 return; 2399 } 2400 2401 /* 2402 * Don't awaken a sleeping thread for SIGSTOP if the 2403 * STOP signal is deferred. 2404 */ 2405 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2406 goto out; 2407 2408 /* 2409 * Give low priority threads a better chance to run. 2410 */ 2411 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2412 sched_prio(td, PUSER); 2413 2414 wakeup_swapper = sleepq_abort(td, intrval); 2415 } else { 2416 /* 2417 * Other states do nothing with the signal immediately, 2418 * other than kicking ourselves if we are running. 2419 * It will either never be noticed, or noticed very soon. 2420 */ 2421 #ifdef SMP 2422 if (TD_IS_RUNNING(td) && td != curthread) 2423 forward_signal(td); 2424 #endif 2425 } 2426 out: 2427 PROC_SUNLOCK(p); 2428 thread_unlock(td); 2429 if (wakeup_swapper) 2430 kick_proc0(); 2431 } 2432 2433 static void 2434 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2435 { 2436 struct thread *td2; 2437 2438 PROC_LOCK_ASSERT(p, MA_OWNED); 2439 PROC_SLOCK_ASSERT(p, MA_OWNED); 2440 2441 FOREACH_THREAD_IN_PROC(p, td2) { 2442 thread_lock(td2); 2443 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2444 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2445 (td2->td_flags & TDF_SINTR)) { 2446 if (td2->td_flags & TDF_SBDRY) { 2447 /* 2448 * Once a thread is asleep with 2449 * TDF_SBDRY set, it should never 2450 * become suspended due to this check. 2451 */ 2452 KASSERT(!TD_IS_SUSPENDED(td2), 2453 ("thread with deferred stops suspended")); 2454 } else if (!TD_IS_SUSPENDED(td2)) { 2455 thread_suspend_one(td2); 2456 } 2457 } else if (!TD_IS_SUSPENDED(td2)) { 2458 if (sending || td != td2) 2459 td2->td_flags |= TDF_ASTPENDING; 2460 #ifdef SMP 2461 if (TD_IS_RUNNING(td2) && td2 != td) 2462 forward_signal(td2); 2463 #endif 2464 } 2465 thread_unlock(td2); 2466 } 2467 } 2468 2469 int 2470 ptracestop(struct thread *td, int sig) 2471 { 2472 struct proc *p = td->td_proc; 2473 2474 PROC_LOCK_ASSERT(p, MA_OWNED); 2475 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2476 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2477 &p->p_mtx.lock_object, "Stopping for traced signal"); 2478 2479 td->td_dbgflags |= TDB_XSIG; 2480 td->td_xsig = sig; 2481 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2482 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2483 PROC_SLOCK(p); 2484 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2485 if (p->p_flag & P_SINGLE_EXIT) { 2486 td->td_dbgflags &= ~TDB_XSIG; 2487 PROC_SUNLOCK(p); 2488 return (sig); 2489 } 2490 /* 2491 * Just make wait() to work, the last stopped thread 2492 * will win. 2493 */ 2494 p->p_xsig = sig; 2495 p->p_xthread = td; 2496 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2497 sig_suspend_threads(td, p, 0); 2498 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2499 td->td_dbgflags &= ~TDB_STOPATFORK; 2500 cv_broadcast(&p->p_dbgwait); 2501 } 2502 stopme: 2503 thread_suspend_switch(td, p); 2504 if (p->p_xthread == td) 2505 p->p_xthread = NULL; 2506 if (!(p->p_flag & P_TRACED)) 2507 break; 2508 if (td->td_dbgflags & TDB_SUSPEND) { 2509 if (p->p_flag & P_SINGLE_EXIT) 2510 break; 2511 goto stopme; 2512 } 2513 } 2514 PROC_SUNLOCK(p); 2515 return (td->td_xsig); 2516 } 2517 2518 static void 2519 reschedule_signals(struct proc *p, sigset_t block, int flags) 2520 { 2521 struct sigacts *ps; 2522 struct thread *td; 2523 int sig; 2524 2525 PROC_LOCK_ASSERT(p, MA_OWNED); 2526 ps = p->p_sigacts; 2527 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2528 MA_OWNED : MA_NOTOWNED); 2529 if (SIGISEMPTY(p->p_siglist)) 2530 return; 2531 SIGSETAND(block, p->p_siglist); 2532 while ((sig = sig_ffs(&block)) != 0) { 2533 SIGDELSET(block, sig); 2534 td = sigtd(p, sig, 0); 2535 signotify(td); 2536 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2537 mtx_lock(&ps->ps_mtx); 2538 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2539 tdsigwakeup(td, sig, SIG_CATCH, 2540 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2541 ERESTART)); 2542 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2543 mtx_unlock(&ps->ps_mtx); 2544 } 2545 } 2546 2547 void 2548 tdsigcleanup(struct thread *td) 2549 { 2550 struct proc *p; 2551 sigset_t unblocked; 2552 2553 p = td->td_proc; 2554 PROC_LOCK_ASSERT(p, MA_OWNED); 2555 2556 sigqueue_flush(&td->td_sigqueue); 2557 if (p->p_numthreads == 1) 2558 return; 2559 2560 /* 2561 * Since we cannot handle signals, notify signal post code 2562 * about this by filling the sigmask. 2563 * 2564 * Also, if needed, wake up thread(s) that do not block the 2565 * same signals as the exiting thread, since the thread might 2566 * have been selected for delivery and woken up. 2567 */ 2568 SIGFILLSET(unblocked); 2569 SIGSETNAND(unblocked, td->td_sigmask); 2570 SIGFILLSET(td->td_sigmask); 2571 reschedule_signals(p, unblocked, 0); 2572 2573 } 2574 2575 /* 2576 * Defer the delivery of SIGSTOP for the current thread. Returns true 2577 * if stops were deferred and false if they were already deferred. 2578 */ 2579 int 2580 sigdeferstop(void) 2581 { 2582 struct thread *td; 2583 2584 td = curthread; 2585 if (td->td_flags & TDF_SBDRY) 2586 return (0); 2587 thread_lock(td); 2588 td->td_flags |= TDF_SBDRY; 2589 thread_unlock(td); 2590 return (1); 2591 } 2592 2593 /* 2594 * Permit the delivery of SIGSTOP for the current thread. This does 2595 * not immediately suspend if a stop was posted. Instead, the thread 2596 * will suspend either via ast() or a subsequent interruptible sleep. 2597 */ 2598 int 2599 sigallowstop(void) 2600 { 2601 struct thread *td; 2602 int prev; 2603 2604 td = curthread; 2605 thread_lock(td); 2606 prev = (td->td_flags & TDF_SBDRY) != 0; 2607 td->td_flags &= ~TDF_SBDRY; 2608 thread_unlock(td); 2609 return (prev); 2610 } 2611 2612 /* 2613 * If the current process has received a signal (should be caught or cause 2614 * termination, should interrupt current syscall), return the signal number. 2615 * Stop signals with default action are processed immediately, then cleared; 2616 * they aren't returned. This is checked after each entry to the system for 2617 * a syscall or trap (though this can usually be done without calling issignal 2618 * by checking the pending signal masks in cursig.) The normal call 2619 * sequence is 2620 * 2621 * while (sig = cursig(curthread)) 2622 * postsig(sig); 2623 */ 2624 static int 2625 issignal(struct thread *td) 2626 { 2627 struct proc *p; 2628 struct sigacts *ps; 2629 struct sigqueue *queue; 2630 sigset_t sigpending; 2631 int sig, prop, newsig; 2632 2633 p = td->td_proc; 2634 ps = p->p_sigacts; 2635 mtx_assert(&ps->ps_mtx, MA_OWNED); 2636 PROC_LOCK_ASSERT(p, MA_OWNED); 2637 for (;;) { 2638 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2639 2640 sigpending = td->td_sigqueue.sq_signals; 2641 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2642 SIGSETNAND(sigpending, td->td_sigmask); 2643 2644 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2645 SIG_STOPSIGMASK(sigpending); 2646 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2647 return (0); 2648 sig = sig_ffs(&sigpending); 2649 2650 if (p->p_stops & S_SIG) { 2651 mtx_unlock(&ps->ps_mtx); 2652 stopevent(p, S_SIG, sig); 2653 mtx_lock(&ps->ps_mtx); 2654 } 2655 2656 /* 2657 * We should see pending but ignored signals 2658 * only if P_TRACED was on when they were posted. 2659 */ 2660 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2661 sigqueue_delete(&td->td_sigqueue, sig); 2662 sigqueue_delete(&p->p_sigqueue, sig); 2663 continue; 2664 } 2665 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2666 /* 2667 * If traced, always stop. 2668 * Remove old signal from queue before the stop. 2669 * XXX shrug off debugger, it causes siginfo to 2670 * be thrown away. 2671 */ 2672 queue = &td->td_sigqueue; 2673 td->td_dbgksi.ksi_signo = 0; 2674 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2675 queue = &p->p_sigqueue; 2676 sigqueue_get(queue, sig, &td->td_dbgksi); 2677 } 2678 2679 mtx_unlock(&ps->ps_mtx); 2680 newsig = ptracestop(td, sig); 2681 mtx_lock(&ps->ps_mtx); 2682 2683 if (sig != newsig) { 2684 2685 /* 2686 * If parent wants us to take the signal, 2687 * then it will leave it in p->p_xsig; 2688 * otherwise we just look for signals again. 2689 */ 2690 if (newsig == 0) 2691 continue; 2692 sig = newsig; 2693 2694 /* 2695 * Put the new signal into td_sigqueue. If the 2696 * signal is being masked, look for other 2697 * signals. 2698 */ 2699 sigqueue_add(queue, sig, NULL); 2700 if (SIGISMEMBER(td->td_sigmask, sig)) 2701 continue; 2702 signotify(td); 2703 } else { 2704 if (td->td_dbgksi.ksi_signo != 0) { 2705 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2706 if (sigqueue_add(&td->td_sigqueue, sig, 2707 &td->td_dbgksi) != 0) 2708 td->td_dbgksi.ksi_signo = 0; 2709 } 2710 if (td->td_dbgksi.ksi_signo == 0) 2711 sigqueue_add(&td->td_sigqueue, sig, 2712 NULL); 2713 } 2714 2715 /* 2716 * If the traced bit got turned off, go back up 2717 * to the top to rescan signals. This ensures 2718 * that p_sig* and p_sigact are consistent. 2719 */ 2720 if ((p->p_flag & P_TRACED) == 0) 2721 continue; 2722 } 2723 2724 prop = sigprop(sig); 2725 2726 /* 2727 * Decide whether the signal should be returned. 2728 * Return the signal's number, or fall through 2729 * to clear it from the pending mask. 2730 */ 2731 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2732 2733 case (intptr_t)SIG_DFL: 2734 /* 2735 * Don't take default actions on system processes. 2736 */ 2737 if (p->p_pid <= 1) { 2738 #ifdef DIAGNOSTIC 2739 /* 2740 * Are you sure you want to ignore SIGSEGV 2741 * in init? XXX 2742 */ 2743 printf("Process (pid %lu) got signal %d\n", 2744 (u_long)p->p_pid, sig); 2745 #endif 2746 break; /* == ignore */ 2747 } 2748 /* 2749 * If there is a pending stop signal to process 2750 * with default action, stop here, 2751 * then clear the signal. However, 2752 * if process is member of an orphaned 2753 * process group, ignore tty stop signals. 2754 */ 2755 if (prop & SA_STOP) { 2756 if (p->p_flag & (P_TRACED|P_WEXIT) || 2757 (p->p_pgrp->pg_jobc == 0 && 2758 prop & SA_TTYSTOP)) 2759 break; /* == ignore */ 2760 mtx_unlock(&ps->ps_mtx); 2761 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2762 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2763 p->p_flag |= P_STOPPED_SIG; 2764 p->p_xsig = sig; 2765 PROC_SLOCK(p); 2766 sig_suspend_threads(td, p, 0); 2767 thread_suspend_switch(td, p); 2768 PROC_SUNLOCK(p); 2769 mtx_lock(&ps->ps_mtx); 2770 break; 2771 } else if (prop & SA_IGNORE) { 2772 /* 2773 * Except for SIGCONT, shouldn't get here. 2774 * Default action is to ignore; drop it. 2775 */ 2776 break; /* == ignore */ 2777 } else 2778 return (sig); 2779 /*NOTREACHED*/ 2780 2781 case (intptr_t)SIG_IGN: 2782 /* 2783 * Masking above should prevent us ever trying 2784 * to take action on an ignored signal other 2785 * than SIGCONT, unless process is traced. 2786 */ 2787 if ((prop & SA_CONT) == 0 && 2788 (p->p_flag & P_TRACED) == 0) 2789 printf("issignal\n"); 2790 break; /* == ignore */ 2791 2792 default: 2793 /* 2794 * This signal has an action, let 2795 * postsig() process it. 2796 */ 2797 return (sig); 2798 } 2799 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2800 sigqueue_delete(&p->p_sigqueue, sig); 2801 } 2802 /* NOTREACHED */ 2803 } 2804 2805 void 2806 thread_stopped(struct proc *p) 2807 { 2808 int n; 2809 2810 PROC_LOCK_ASSERT(p, MA_OWNED); 2811 PROC_SLOCK_ASSERT(p, MA_OWNED); 2812 n = p->p_suspcount; 2813 if (p == curproc) 2814 n++; 2815 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2816 PROC_SUNLOCK(p); 2817 p->p_flag &= ~P_WAITED; 2818 PROC_LOCK(p->p_pptr); 2819 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2820 CLD_TRAPPED : CLD_STOPPED); 2821 PROC_UNLOCK(p->p_pptr); 2822 PROC_SLOCK(p); 2823 } 2824 } 2825 2826 /* 2827 * Take the action for the specified signal 2828 * from the current set of pending signals. 2829 */ 2830 int 2831 postsig(sig) 2832 register int sig; 2833 { 2834 struct thread *td = curthread; 2835 register struct proc *p = td->td_proc; 2836 struct sigacts *ps; 2837 sig_t action; 2838 ksiginfo_t ksi; 2839 sigset_t returnmask; 2840 2841 KASSERT(sig != 0, ("postsig")); 2842 2843 PROC_LOCK_ASSERT(p, MA_OWNED); 2844 ps = p->p_sigacts; 2845 mtx_assert(&ps->ps_mtx, MA_OWNED); 2846 ksiginfo_init(&ksi); 2847 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2848 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2849 return (0); 2850 ksi.ksi_signo = sig; 2851 if (ksi.ksi_code == SI_TIMER) 2852 itimer_accept(p, ksi.ksi_timerid, &ksi); 2853 action = ps->ps_sigact[_SIG_IDX(sig)]; 2854 #ifdef KTRACE 2855 if (KTRPOINT(td, KTR_PSIG)) 2856 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2857 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2858 #endif 2859 if (p->p_stops & S_SIG) { 2860 mtx_unlock(&ps->ps_mtx); 2861 stopevent(p, S_SIG, sig); 2862 mtx_lock(&ps->ps_mtx); 2863 } 2864 2865 if (action == SIG_DFL) { 2866 /* 2867 * Default action, where the default is to kill 2868 * the process. (Other cases were ignored above.) 2869 */ 2870 mtx_unlock(&ps->ps_mtx); 2871 sigexit(td, sig); 2872 /* NOTREACHED */ 2873 } else { 2874 /* 2875 * If we get here, the signal must be caught. 2876 */ 2877 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2878 ("postsig action")); 2879 /* 2880 * Set the new mask value and also defer further 2881 * occurrences of this signal. 2882 * 2883 * Special case: user has done a sigsuspend. Here the 2884 * current mask is not of interest, but rather the 2885 * mask from before the sigsuspend is what we want 2886 * restored after the signal processing is completed. 2887 */ 2888 if (td->td_pflags & TDP_OLDMASK) { 2889 returnmask = td->td_oldsigmask; 2890 td->td_pflags &= ~TDP_OLDMASK; 2891 } else 2892 returnmask = td->td_sigmask; 2893 2894 if (p->p_sig == sig) { 2895 p->p_code = 0; 2896 p->p_sig = 0; 2897 } 2898 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2899 postsig_done(sig, td, ps); 2900 } 2901 return (1); 2902 } 2903 2904 /* 2905 * Kill the current process for stated reason. 2906 */ 2907 void 2908 killproc(p, why) 2909 struct proc *p; 2910 char *why; 2911 { 2912 2913 PROC_LOCK_ASSERT(p, MA_OWNED); 2914 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2915 p->p_comm); 2916 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2917 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2918 p->p_flag |= P_WKILLED; 2919 kern_psignal(p, SIGKILL); 2920 } 2921 2922 /* 2923 * Force the current process to exit with the specified signal, dumping core 2924 * if appropriate. We bypass the normal tests for masked and caught signals, 2925 * allowing unrecoverable failures to terminate the process without changing 2926 * signal state. Mark the accounting record with the signal termination. 2927 * If dumping core, save the signal number for the debugger. Calls exit and 2928 * does not return. 2929 */ 2930 void 2931 sigexit(td, sig) 2932 struct thread *td; 2933 int sig; 2934 { 2935 struct proc *p = td->td_proc; 2936 2937 PROC_LOCK_ASSERT(p, MA_OWNED); 2938 p->p_acflag |= AXSIG; 2939 /* 2940 * We must be single-threading to generate a core dump. This 2941 * ensures that the registers in the core file are up-to-date. 2942 * Also, the ELF dump handler assumes that the thread list doesn't 2943 * change out from under it. 2944 * 2945 * XXX If another thread attempts to single-thread before us 2946 * (e.g. via fork()), we won't get a dump at all. 2947 */ 2948 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 2949 p->p_sig = sig; 2950 /* 2951 * Log signals which would cause core dumps 2952 * (Log as LOG_INFO to appease those who don't want 2953 * these messages.) 2954 * XXX : Todo, as well as euid, write out ruid too 2955 * Note that coredump() drops proc lock. 2956 */ 2957 if (coredump(td) == 0) 2958 sig |= WCOREFLAG; 2959 if (kern_logsigexit) 2960 log(LOG_INFO, 2961 "pid %d (%s), uid %d: exited on signal %d%s\n", 2962 p->p_pid, p->p_comm, 2963 td->td_ucred ? td->td_ucred->cr_uid : -1, 2964 sig &~ WCOREFLAG, 2965 sig & WCOREFLAG ? " (core dumped)" : ""); 2966 } else 2967 PROC_UNLOCK(p); 2968 exit1(td, 0, sig); 2969 /* NOTREACHED */ 2970 } 2971 2972 /* 2973 * Send queued SIGCHLD to parent when child process's state 2974 * is changed. 2975 */ 2976 static void 2977 sigparent(struct proc *p, int reason, int status) 2978 { 2979 PROC_LOCK_ASSERT(p, MA_OWNED); 2980 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2981 2982 if (p->p_ksi != NULL) { 2983 p->p_ksi->ksi_signo = SIGCHLD; 2984 p->p_ksi->ksi_code = reason; 2985 p->p_ksi->ksi_status = status; 2986 p->p_ksi->ksi_pid = p->p_pid; 2987 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2988 if (KSI_ONQ(p->p_ksi)) 2989 return; 2990 } 2991 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2992 } 2993 2994 static void 2995 childproc_jobstate(struct proc *p, int reason, int sig) 2996 { 2997 struct sigacts *ps; 2998 2999 PROC_LOCK_ASSERT(p, MA_OWNED); 3000 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3001 3002 /* 3003 * Wake up parent sleeping in kern_wait(), also send 3004 * SIGCHLD to parent, but SIGCHLD does not guarantee 3005 * that parent will awake, because parent may masked 3006 * the signal. 3007 */ 3008 p->p_pptr->p_flag |= P_STATCHILD; 3009 wakeup(p->p_pptr); 3010 3011 ps = p->p_pptr->p_sigacts; 3012 mtx_lock(&ps->ps_mtx); 3013 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3014 mtx_unlock(&ps->ps_mtx); 3015 sigparent(p, reason, sig); 3016 } else 3017 mtx_unlock(&ps->ps_mtx); 3018 } 3019 3020 void 3021 childproc_stopped(struct proc *p, int reason) 3022 { 3023 3024 childproc_jobstate(p, reason, p->p_xsig); 3025 } 3026 3027 void 3028 childproc_continued(struct proc *p) 3029 { 3030 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3031 } 3032 3033 void 3034 childproc_exited(struct proc *p) 3035 { 3036 int reason, status; 3037 3038 if (WCOREDUMP(p->p_xsig)) { 3039 reason = CLD_DUMPED; 3040 status = WTERMSIG(p->p_xsig); 3041 } else if (WIFSIGNALED(p->p_xsig)) { 3042 reason = CLD_KILLED; 3043 status = WTERMSIG(p->p_xsig); 3044 } else { 3045 reason = CLD_EXITED; 3046 status = p->p_xexit; 3047 } 3048 /* 3049 * XXX avoid calling wakeup(p->p_pptr), the work is 3050 * done in exit1(). 3051 */ 3052 sigparent(p, reason, status); 3053 } 3054 3055 /* 3056 * We only have 1 character for the core count in the format 3057 * string, so the range will be 0-9 3058 */ 3059 #define MAX_NUM_CORES 10 3060 static int num_cores = 5; 3061 3062 static int 3063 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3064 { 3065 int error; 3066 int new_val; 3067 3068 new_val = num_cores; 3069 error = sysctl_handle_int(oidp, &new_val, 0, req); 3070 if (error != 0 || req->newptr == NULL) 3071 return (error); 3072 if (new_val > MAX_NUM_CORES) 3073 new_val = MAX_NUM_CORES; 3074 if (new_val < 0) 3075 new_val = 0; 3076 num_cores = new_val; 3077 return (0); 3078 } 3079 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3080 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3081 3082 #define GZ_SUFFIX ".gz" 3083 3084 #ifdef GZIO 3085 static int compress_user_cores = 1; 3086 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN, 3087 &compress_user_cores, 0, "Compression of user corefiles"); 3088 3089 int compress_user_cores_gzlevel = 6; 3090 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN, 3091 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level"); 3092 #else 3093 static int compress_user_cores = 0; 3094 #endif 3095 3096 /* 3097 * Protect the access to corefilename[] by allproc_lock. 3098 */ 3099 #define corefilename_lock allproc_lock 3100 3101 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3102 3103 static int 3104 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3105 { 3106 int error; 3107 3108 sx_xlock(&corefilename_lock); 3109 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3110 req); 3111 sx_xunlock(&corefilename_lock); 3112 3113 return (error); 3114 } 3115 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RWTUN | 3116 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3117 "Process corefile name format string"); 3118 3119 /* 3120 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3121 * Expand the name described in corefilename, using name, uid, and pid 3122 * and open/create core file. 3123 * corefilename is a printf-like string, with three format specifiers: 3124 * %N name of process ("name") 3125 * %P process id (pid) 3126 * %U user id (uid) 3127 * For example, "%N.core" is the default; they can be disabled completely 3128 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3129 * This is controlled by the sysctl variable kern.corefile (see above). 3130 */ 3131 static int 3132 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3133 int compress, struct vnode **vpp, char **namep) 3134 { 3135 struct nameidata nd; 3136 struct sbuf sb; 3137 const char *format; 3138 char *hostname, *name; 3139 int indexpos, i, error, cmode, flags, oflags; 3140 3141 hostname = NULL; 3142 format = corefilename; 3143 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3144 indexpos = -1; 3145 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3146 sx_slock(&corefilename_lock); 3147 for (i = 0; format[i] != '\0'; i++) { 3148 switch (format[i]) { 3149 case '%': /* Format character */ 3150 i++; 3151 switch (format[i]) { 3152 case '%': 3153 sbuf_putc(&sb, '%'); 3154 break; 3155 case 'H': /* hostname */ 3156 if (hostname == NULL) { 3157 hostname = malloc(MAXHOSTNAMELEN, 3158 M_TEMP, M_WAITOK); 3159 } 3160 getcredhostname(td->td_ucred, hostname, 3161 MAXHOSTNAMELEN); 3162 sbuf_printf(&sb, "%s", hostname); 3163 break; 3164 case 'I': /* autoincrementing index */ 3165 sbuf_printf(&sb, "0"); 3166 indexpos = sbuf_len(&sb) - 1; 3167 break; 3168 case 'N': /* process name */ 3169 sbuf_printf(&sb, "%s", comm); 3170 break; 3171 case 'P': /* process id */ 3172 sbuf_printf(&sb, "%u", pid); 3173 break; 3174 case 'U': /* user id */ 3175 sbuf_printf(&sb, "%u", uid); 3176 break; 3177 default: 3178 log(LOG_ERR, 3179 "Unknown format character %c in " 3180 "corename `%s'\n", format[i], format); 3181 break; 3182 } 3183 break; 3184 default: 3185 sbuf_putc(&sb, format[i]); 3186 break; 3187 } 3188 } 3189 sx_sunlock(&corefilename_lock); 3190 free(hostname, M_TEMP); 3191 if (compress) 3192 sbuf_printf(&sb, GZ_SUFFIX); 3193 if (sbuf_error(&sb) != 0) { 3194 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3195 "long\n", (long)pid, comm, (u_long)uid); 3196 sbuf_delete(&sb); 3197 free(name, M_TEMP); 3198 return (ENOMEM); 3199 } 3200 sbuf_finish(&sb); 3201 sbuf_delete(&sb); 3202 3203 cmode = S_IRUSR | S_IWUSR; 3204 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3205 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3206 3207 /* 3208 * If the core format has a %I in it, then we need to check 3209 * for existing corefiles before returning a name. 3210 * To do this we iterate over 0..num_cores to find a 3211 * non-existing core file name to use. 3212 */ 3213 if (indexpos != -1) { 3214 for (i = 0; i < num_cores; i++) { 3215 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3216 name[indexpos] = '0' + i; 3217 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3218 error = vn_open_cred(&nd, &flags, cmode, oflags, 3219 td->td_ucred, NULL); 3220 if (error) { 3221 if (error == EEXIST) 3222 continue; 3223 log(LOG_ERR, 3224 "pid %d (%s), uid (%u): Path `%s' failed " 3225 "on initial open test, error = %d\n", 3226 pid, comm, uid, name, error); 3227 } 3228 goto out; 3229 } 3230 } 3231 3232 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3233 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3234 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3235 out: 3236 if (error) { 3237 #ifdef AUDIT 3238 audit_proc_coredump(td, name, error); 3239 #endif 3240 free(name, M_TEMP); 3241 return (error); 3242 } 3243 NDFREE(&nd, NDF_ONLY_PNBUF); 3244 *vpp = nd.ni_vp; 3245 *namep = name; 3246 return (0); 3247 } 3248 3249 static int 3250 coredump_sanitise_path(const char *path) 3251 { 3252 size_t i; 3253 3254 /* 3255 * Only send a subset of ASCII to devd(8) because it 3256 * might pass these strings to sh -c. 3257 */ 3258 for (i = 0; path[i]; i++) 3259 if (!(isalpha(path[i]) || isdigit(path[i])) && 3260 path[i] != '/' && path[i] != '.' && 3261 path[i] != '-') 3262 return (0); 3263 3264 return (1); 3265 } 3266 3267 /* 3268 * Dump a process' core. The main routine does some 3269 * policy checking, and creates the name of the coredump; 3270 * then it passes on a vnode and a size limit to the process-specific 3271 * coredump routine if there is one; if there _is not_ one, it returns 3272 * ENOSYS; otherwise it returns the error from the process-specific routine. 3273 */ 3274 3275 static int 3276 coredump(struct thread *td) 3277 { 3278 struct proc *p = td->td_proc; 3279 struct ucred *cred = td->td_ucred; 3280 struct vnode *vp; 3281 struct flock lf; 3282 struct vattr vattr; 3283 int error, error1, locked; 3284 char *name; /* name of corefile */ 3285 void *rl_cookie; 3286 off_t limit; 3287 char *data = NULL; 3288 char *fullpath, *freepath = NULL; 3289 size_t len; 3290 static const char comm_name[] = "comm="; 3291 static const char core_name[] = "core="; 3292 3293 PROC_LOCK_ASSERT(p, MA_OWNED); 3294 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3295 _STOPEVENT(p, S_CORE, 0); 3296 3297 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3298 (p->p_flag2 & P2_NOTRACE) != 0) { 3299 PROC_UNLOCK(p); 3300 return (EFAULT); 3301 } 3302 3303 /* 3304 * Note that the bulk of limit checking is done after 3305 * the corefile is created. The exception is if the limit 3306 * for corefiles is 0, in which case we don't bother 3307 * creating the corefile at all. This layout means that 3308 * a corefile is truncated instead of not being created, 3309 * if it is larger than the limit. 3310 */ 3311 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3312 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3313 PROC_UNLOCK(p); 3314 return (EFBIG); 3315 } 3316 PROC_UNLOCK(p); 3317 3318 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3319 compress_user_cores, &vp, &name); 3320 if (error != 0) 3321 return (error); 3322 3323 /* 3324 * Don't dump to non-regular files or files with links. 3325 * Do not dump into system files. 3326 */ 3327 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3328 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3329 VOP_UNLOCK(vp, 0); 3330 error = EFAULT; 3331 goto out; 3332 } 3333 3334 VOP_UNLOCK(vp, 0); 3335 3336 /* Postpone other writers, including core dumps of other processes. */ 3337 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3338 3339 lf.l_whence = SEEK_SET; 3340 lf.l_start = 0; 3341 lf.l_len = 0; 3342 lf.l_type = F_WRLCK; 3343 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3344 3345 VATTR_NULL(&vattr); 3346 vattr.va_size = 0; 3347 if (set_core_nodump_flag) 3348 vattr.va_flags = UF_NODUMP; 3349 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3350 VOP_SETATTR(vp, &vattr, cred); 3351 VOP_UNLOCK(vp, 0); 3352 PROC_LOCK(p); 3353 p->p_acflag |= ACORE; 3354 PROC_UNLOCK(p); 3355 3356 if (p->p_sysent->sv_coredump != NULL) { 3357 error = p->p_sysent->sv_coredump(td, vp, limit, 3358 compress_user_cores ? IMGACT_CORE_COMPRESS : 0); 3359 } else { 3360 error = ENOSYS; 3361 } 3362 3363 if (locked) { 3364 lf.l_type = F_UNLCK; 3365 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3366 } 3367 vn_rangelock_unlock(vp, rl_cookie); 3368 3369 /* 3370 * Notify the userland helper that a process triggered a core dump. 3371 * This allows the helper to run an automated debugging session. 3372 */ 3373 if (error != 0 || coredump_devctl == 0) 3374 goto out; 3375 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3376 sizeof(' ') + sizeof(core_name) - 1; 3377 data = malloc(len, M_TEMP, M_WAITOK); 3378 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3379 goto out; 3380 if (!coredump_sanitise_path(fullpath)) 3381 goto out; 3382 snprintf(data, len, "%s%s ", comm_name, fullpath); 3383 free(freepath, M_TEMP); 3384 freepath = NULL; 3385 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3386 goto out; 3387 if (!coredump_sanitise_path(fullpath)) 3388 goto out; 3389 strlcat(data, core_name, len); 3390 strlcat(data, fullpath, len); 3391 devctl_notify("kernel", "signal", "coredump", data); 3392 out: 3393 error1 = vn_close(vp, FWRITE, cred, td); 3394 if (error == 0) 3395 error = error1; 3396 #ifdef AUDIT 3397 audit_proc_coredump(td, name, error); 3398 #endif 3399 free(freepath, M_TEMP); 3400 free(data, M_TEMP); 3401 free(name, M_TEMP); 3402 return (error); 3403 } 3404 3405 /* 3406 * Nonexistent system call-- signal process (may want to handle it). Flag 3407 * error in case process won't see signal immediately (blocked or ignored). 3408 */ 3409 #ifndef _SYS_SYSPROTO_H_ 3410 struct nosys_args { 3411 int dummy; 3412 }; 3413 #endif 3414 /* ARGSUSED */ 3415 int 3416 nosys(td, args) 3417 struct thread *td; 3418 struct nosys_args *args; 3419 { 3420 struct proc *p = td->td_proc; 3421 3422 PROC_LOCK(p); 3423 tdsignal(td, SIGSYS); 3424 PROC_UNLOCK(p); 3425 return (ENOSYS); 3426 } 3427 3428 /* 3429 * Send a SIGIO or SIGURG signal to a process or process group using stored 3430 * credentials rather than those of the current process. 3431 */ 3432 void 3433 pgsigio(sigiop, sig, checkctty) 3434 struct sigio **sigiop; 3435 int sig, checkctty; 3436 { 3437 ksiginfo_t ksi; 3438 struct sigio *sigio; 3439 3440 ksiginfo_init(&ksi); 3441 ksi.ksi_signo = sig; 3442 ksi.ksi_code = SI_KERNEL; 3443 3444 SIGIO_LOCK(); 3445 sigio = *sigiop; 3446 if (sigio == NULL) { 3447 SIGIO_UNLOCK(); 3448 return; 3449 } 3450 if (sigio->sio_pgid > 0) { 3451 PROC_LOCK(sigio->sio_proc); 3452 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3453 kern_psignal(sigio->sio_proc, sig); 3454 PROC_UNLOCK(sigio->sio_proc); 3455 } else if (sigio->sio_pgid < 0) { 3456 struct proc *p; 3457 3458 PGRP_LOCK(sigio->sio_pgrp); 3459 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3460 PROC_LOCK(p); 3461 if (p->p_state == PRS_NORMAL && 3462 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3463 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3464 kern_psignal(p, sig); 3465 PROC_UNLOCK(p); 3466 } 3467 PGRP_UNLOCK(sigio->sio_pgrp); 3468 } 3469 SIGIO_UNLOCK(); 3470 } 3471 3472 static int 3473 filt_sigattach(struct knote *kn) 3474 { 3475 struct proc *p = curproc; 3476 3477 kn->kn_ptr.p_proc = p; 3478 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3479 3480 knlist_add(&p->p_klist, kn, 0); 3481 3482 return (0); 3483 } 3484 3485 static void 3486 filt_sigdetach(struct knote *kn) 3487 { 3488 struct proc *p = kn->kn_ptr.p_proc; 3489 3490 knlist_remove(&p->p_klist, kn, 0); 3491 } 3492 3493 /* 3494 * signal knotes are shared with proc knotes, so we apply a mask to 3495 * the hint in order to differentiate them from process hints. This 3496 * could be avoided by using a signal-specific knote list, but probably 3497 * isn't worth the trouble. 3498 */ 3499 static int 3500 filt_signal(struct knote *kn, long hint) 3501 { 3502 3503 if (hint & NOTE_SIGNAL) { 3504 hint &= ~NOTE_SIGNAL; 3505 3506 if (kn->kn_id == hint) 3507 kn->kn_data++; 3508 } 3509 return (kn->kn_data != 0); 3510 } 3511 3512 struct sigacts * 3513 sigacts_alloc(void) 3514 { 3515 struct sigacts *ps; 3516 3517 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3518 refcount_init(&ps->ps_refcnt, 1); 3519 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3520 return (ps); 3521 } 3522 3523 void 3524 sigacts_free(struct sigacts *ps) 3525 { 3526 3527 if (refcount_release(&ps->ps_refcnt) == 0) 3528 return; 3529 mtx_destroy(&ps->ps_mtx); 3530 free(ps, M_SUBPROC); 3531 } 3532 3533 struct sigacts * 3534 sigacts_hold(struct sigacts *ps) 3535 { 3536 3537 refcount_acquire(&ps->ps_refcnt); 3538 return (ps); 3539 } 3540 3541 void 3542 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3543 { 3544 3545 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3546 mtx_lock(&src->ps_mtx); 3547 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3548 mtx_unlock(&src->ps_mtx); 3549 } 3550 3551 int 3552 sigacts_shared(struct sigacts *ps) 3553 { 3554 3555 return (ps->ps_refcnt > 1); 3556 } 3557